United States v. Trenkler

                United States Court of Appeals
                            United States Court of Appeals
                    For the First Circuit
                                For the First Circuit
                                         

No. 94-1301

                        UNITED STATES,

                          Appellee,

                              v.

                       ALFRED TRENKLER,

                    Defendant - Appellant.

                                         

         APPEAL FROM THE UNITED STATES DISTRICT COURT

              FOR THE DISTRICT OF MASSACHUSETTS

           [Hon. Rya W. Zobel, U.S. District Judge]
                                                              

                                         

                            Before

                    Torruella, Chief Judge,
                                                      
                Coffin, Senior Circuit Judge,
                                                        
                  and Stahl, Circuit Judge.
                                                      

                                         

Morris M.  Goldings with whom  Amy J. Axelrod, R.  David Beck, and
                                                                         
Mahoney, Hawkes & Goldings were on brief for appellant.
                                  
Paul  V. Kelly, Assistant  United States Attorney, with whom Frank
                                                                              
A. Libby, Jr., Assistant  United States Attorney and Donald  K. Stern,
                                                                             
United States Attorney, were on brief for appellee.

                                         

                        July 18, 1995
                                         


          STAHL, Circuit Judge.  Following a lengthy criminal
                      STAHL, Circuit Judge.
                                          

trial, a jury convicted  defendant Alfred Trenkler of various

charges  stemming  from  a  bomb  explosion  in   Roslindale,

Massachusetts ("the Roslindale  bomb").  On  appeal, Trenkler

challenges  the  admission  of   evidence  relating  to   his

participation  in a  prior bombing  that occurred  five years

earlier  in  Quincy,   Massachusetts  ("the  Quincy   bomb").

Trenkler  also  assigns  error  to  two  evidentiary  rulings

admitting evidence  derived  from a  computer  database  that

purported to  establish that  Trenkler built both  the Quincy

and  the Roslindale bombs and several out-of-court statements

made by a fellow  participant in the bombing.   After careful

review, we affirm.

                              I.
                                          I.
                                            

                          Background
                                      Background
                                                

          On  October  28,  1991,  a  bomb  exploded  at  the

Roslindale home of Thomas L.  Shay ("Shay Sr."), killing  one

Boston police officer and severely injuring another.  The two

officers, members of the Boston Police Department Bomb Squad,

had been  dispatched  to Shay  Sr.'s  home to  investigate  a

suspicious object located  in Shay Sr.'s driveway.   Shay Sr.

had  earlier  reported that,  while  backing  his 1986  Buick

Century  into the street the day  before, he had heard a loud

noise   emanating  from   beneath   the  floorboard   of  his

                             -2-
                                          2


automobile.  Shay Sr. added that,  subsequently, he found the

suspicious object resting near the crest of his driveway.

          Following  the  explosion, a  massive investigation

ensued involving  a variety of federal, state  and local law-

enforcement agencies.   On June 24,  1993, this investigation

culminated  with  the  return  of  a  three-count  indictment

charging Trenkler and Thomas A. Shay ("Shay Jr."), Shay Sr.'s

son,   with  responsibility  for   the  Roslindale  bombing.1

Trenkler  filed  a  successful  severance  motion,   and  the

government tried the two defendants separately.  Shay Jr. was

tried first, and a jury convicted him on counts of conspiracy

and   malicious   destruction   of  property   by   means  of

explosives.2

          At Trenkler's trial, the thrust of the government's

case was that Trenkler had built the Roslindale bomb for Shay

Jr.  to  use against  his  father.   To  establish Trenkler's

identity as the builder of the bomb,  the government offered,

inter alia, evidence that Trenkler had previously constructed
                      

                    
                                

1.  The  June  24,   1993,  indictment  specifically  charged
Trenkler and  Shay  Jr. with  conspiracy,  18 U.S.C.     371;
receipt of explosive materials with knowledge and intent that
they  would be used to kill, injure and intimidate, and cause
damage to real and personal property, 18 U.S.C.   844(d); and
malicious destruction of property  by means of explosives; 18
U.S.C.    844(i).    The indictment  superseded a  five-count
indictment initially returned against  Trenkler and Shay  Jr.
on December 16, 1992.

2.  The  district  court  sentenced  Shay  Jr.  to concurrent
sentences of 188 and 60 months.  

                             -3-
                                          3


a remote-control  device, the Quincy bomb,  which exploded in

Quincy, Massachusetts,  in  1986.   The government  contended

that unique similarities in design, choice of components, and

overall modus  operandi between  the two bombs  compelled the
                                   

conclusion that Trenkler had designed and built both devices.

Prior  to trial,  the  government filed  a  motion in  limine
                                                                         

seeking to admit the "similarity" evidence.  Following a day-

long  evidentiary  hearing,  the  district  court  ruled  the

evidence  admissible, finding  that  it was  relevant on  the

issues of  identity, skill, knowledge, and  intent.  Although

Trenkler  did not testify at trial, his counsel stipulated at

the evidentiary  hearing that  Trenkler had built  the Quincy

bomb.3  

1986 Quincy Bomb
            1986 Quincy Bomb
                            

          Trenkler constructed the Quincy  bomb in 1986 for a

friend,  Donna Shea.   At  the time,  Shea was involved  in a

dispute  with the owners of  the Capeway Fish  Market and she

wanted the bomb to use as a means to intimidate them.  At her

request, Trenkler assembled a remote-control, radio-activated

explosive device.    The device  was  later attached  to  the

undercarriage of a truck belonging to the Capeway Fish Market

                    
                                

3.  During  the  original  1986 investigation  of  the Quincy
bombing, Trenkler admitted building  the bomb.  In  1987, the
Commonwealth   of   Massachusetts  brought   charges  against
Trenkler for his  involvement in the Quincy bombing,  but the
charges were dismissed.

                             -4-
                                          4


and detonated in the middle of the night.  The resulting bomb

blast caused no injuries and little property damage.

          In building  the Quincy bomb, Trenkler  used as the

explosive  material  a  military  flash  simulator  typically

utilized to  mimic gunfire in  combat exercises.   To provide

remote-control  capabilities,  Trenkler  employed   a  radio-

receiver  he  had removed  from a  small  toy car.   Trenkler

wrapped the bomb  in duct  tape and attached  a large  donut-

shaped speaker magnet  to enable  the bomb to  adhere to  the

undercarriage of  the truck.  Other  components Trenkler used

included a  "double throw" toggle switch,  four AA batteries,

two six-volt  batteries, an  electric relay, solder,  various

wires, and a slide switch.

          Testimony  at  trial   established  that   Trenkler

purchased some  of the  electrical components for  the Quincy

bomb from a  Radio Shack  store.  On  one occasion,  Trenkler

sought to obtain needed  components by sending Shea's eleven-

year-old nephew into a Radio Shack store with a list of items

to purchase while Trenkler  remained waiting outside.  Shea's

nephew, however, was  unable to  find all of  the items,  and

Trenkler eventually came into the store to assist him.  

1991 Roslindale Bomb
            1991 Roslindale Bomb
                                

          The  government contended  that Trenkler  built the

Roslindale  bomb  at  Shay  Jr.'s  request.    At trial,  the

government  offered  evidence  about Trenkler's  relationship

                             -5-
                                          5


with Shay  Jr., dating back  at least two years  prior to the

Roslindale bombing.  Several witnesses,  including Trenkler's

business  partner,  reported  seeing  the  two  together   on

different  occasions in  1990 and 1991.   Shay  Jr.'s address

book included an entry for Trenkler listing his current pager

number.   Moreover, Trenkler's roommate  at the  time of  the

Roslindale  bombing  testified  that,  during  September  and

October of 1991, Shay Jr. left several voice-mail messages on

the pager for Trenkler.    

          Testimony  from  government investigators  and Shay

Sr.  established  that  the  Roslindale bomb  was  a  remote-

control,  radio-activated  device  with  an  explosive  force

supplied  by two or three sticks of dynamite connected to two

electrical blasting caps.  A black wooden box weighing two or

three pounds and measuring approximately eight- to ten-inches

long, five- to  six-inches wide and  one- to two-inches  deep

housed  the bomb.   A large  donut-shaped magnet  and several

smaller round magnets attached to the box were used to secure

the  device to the underside of Shay Sr.'s automobile.  Other

components used in the construction of the bomb included duct

tape, a "single throw" toggle switch, four AA batteries, five

nine-volt batteries, a Futaba radio receiver, solder, various

wires, and a slide switch.  

          According to the government's experts and Shay Sr.,

the bomb was originally attached to the undercarriage of Shay

                             -6-
                                          6


Sr.'s  automobile directly  beneath the  driver's seat.   The

government's explosives expert testified that if the bomb had

exploded while still  attached to the car,  it probably would

have  killed or  at  least seriously  injured any  individual

sitting in the driver's seat.

          The  government also  asserted  that Trenkler  used

Shay Jr. to  purchase the electronic  components used in  the

bomb.     In  support  of  this   assertion,  the  government

introduced a sales receipt  for a toggle switch purchased  in

October 1991 at a Radio Shack store located across the street

from  where Trenkler, at the time, was installing a satellite

dish.4    Agents from  the  Bureau  of Alcohol,  Tobacco  and

Firearms ("ATF") recovered from  the debris of the Roslindale

bomb  a  switch identical  to the  one  purchased.   Shay Jr.

admitted  purchasing  the switch  during  a  taped television

interview, portions  of  which the  government introduced  at

trial.5    Furthermore,  a  sales clerk  at  the  Radio Shack

testified that,  prior to  purchasing the switch,  the person

                    
                                

4.  Trenkler has an extensive  background in electronics.  At
the time of the Roslindale bomb, he operated his own business
installing satellite dishes and other electronic equipment.

5.  The Radio Shack sales receipt has the  letters "sahy jyt"
printed in a space  for the customer's address and  lists the
customer's  "ID"   number  (the  last  four   digits  of  the
customer's phone number) as "3780."  The government maintains
that this corroborates Shay Jr.'s statement that he purchased
components for the bomb because "sahy" is a  transposition of
"Shay" and "3780" is a transposition of "7380," the last four
digits of Shay Sr.'s phone number. 

                             -7-
                                          7


who bought it had  browsed in the store for  several minutes,

appearing  to shop  for items written  on a list.   The sales

clerk also testified that he  recalled seeing Trenkler in the

store on two or three occasions during the fall of 1991.

          Both the government and Trenkler elicited testimony

from  their  respective  explosives  experts  explaining  the

similarities  and differences  between the  two bombs.   Both

experts   testified  at  length   concerning  the  electronic

designs,  the   choice  of  components  and   the  method  of

construction.   The government's  expert opined that  the two

incidents shared  many  similar traits  and  characteristics,

evincing  the "signature" of a single bomb maker.  He further

stated that he had no doubt "whatsoever" that the same person

built  both bombs.   Trenkler's  expert, on  the other  hand,

stated that too many dissimilarities existed to conclude that

the  same  person built  both  bombs.   Moreover,  Trenkler's

expert testified  that the similarities  that existed  lacked

sufficient distinguishing qualities to identify the two bombs

as the handiwork of a specific individual.

EXIS Computer Database Evidence
            EXIS Computer Database Evidence
                                           

          To support  the inference that Trenkler  built both

bombs, the government offered  testimony both at the pretrial

hearing and at trial concerning information retrieved from an

ATF  computer database  of  explosives and  arson  incidents.

Stephen Scheid, an Intelligence Research Specialist with ATF,

                             -8-
                                          8


testified  that  the   database,  known  as  EXIS,   contains

information taken  from reports  submitted to ATF  by various

federal, state  and local law-enforcement  agencies.   Scheid

further testified that he had been personally responsible for

maintaining the database  since 1977.  Scheid  stated that he

reviews  submitted   incident  reports,  culling   from  them

information describing the characteristics of each bombing or

arson  episode.    Scheid  added  that  he then  encodes  the

extracted  information on a  standardized worksheet, which he

or  a data-entry person in turn uses to enter the information

into the database.

          Scheid  testified   that,  through  the  use  of  a

computer  program, he  then produces  investigatory leads  by

retrieving  all incidents  entered in  the database  that are

listed as possessing a specific  component or characteristic.

Scheid  further testified that, in  an effort to identify the

builder of  the  Roslindale bomb,  he performed  a series  of

computer   queries,  focusing   on  characteristics   of  the

Roslindale bomb.  This series of inquiries narrowed the field

of  reported incidents in the database from 40,867 to seven.6

                    
                                

6.  The computer  queries and  the total number  of resulting
incidents are listed below.  The queries are successive.

          All incidents in database       - 40,867

          Bombings and attempted bombings - 14,252

          Involving cars and trucks       -  2,504

                             -9-
                                          9


The seven remaining  incidents included  both the  Roslindale

and  Quincy  bombs.    Scheid  stated  that  he  subsequently

conducted a  manual analysis  of the remaining  incidents and

was  able  to  identify  several  additional  characteristics

common to only the Roslindale and Quincy bombs.7

          Scheid also testified that the report of the Quincy

bomb did not come to his attention through normal procedures.

Scheid  did not  receive  information about  the 1986  Quincy

bomb,  nor enter  any information  pertaining to it  into the

EXIS database, until after the Roslindale incident in 1991.8

Other Trial Evidence   
            Other Trial Evidence
                                

          The government  also offered the testimony of David

Lindholm to establish that  Trenkler had built the Roslindale

bomb.    Lindholm  testified  that he  met  Trenkler  at  the

                    
                                

          Under vehicles                  -    428

          Remote-control                  -     19

          Using magnets                   -      7

7.  Scheid testified that, of  the seven remaining incidents,
only  the Roslindale  and the  Quincy bomb  were reported  as
possessing  all  of  the  additional features:    duct  tape,
soldering,  AA   batteries,  toggle  switches,   and  "round"
magnets.

8.  Scheid testified that, in entering information about  the
Quincy  bombing into the EXIS database, he relied solely on a
laboratory report prepared in  1986 by investigators from the
Massachusetts  Department  of Public  Safety.    This report,
however,  does not state that the Quincy bomb was attached to
the  underside of the  Capeway truck.  It  only refers to the
bomb as an "[e]xplosion on truck."  Nevertheless, Scheid used
"under vehicle" as  one of the computer queries  that matched
the Quincy and Roslindale bombings.

                             -10-
                                          10


Plymouth House of Correction  where they had spent  four days

incarcerated together in an uncomfortable orientation holding

cell in December 1992.  Lindholm testified that initially the

cell had held about forty-four prisoners, but that eventually

the total number  of prisoners in the cell dwindled to six or

seven.   Lindholm  added that  he had  numerous conversations

with  Trenkler over  the  course of  the  four days  as  they

gradually "bonded"  upon discovering that they  came from the

same home town and had similar backgrounds.  

          Lindholm  testified that  he  gave  Trenkler  legal

advice based on  his own experience as a  criminal defendant.

Lindholm  acknowledged that  Trenkler initially  asserted his

innocence and had maintained that he could not understand why

Shay  Jr. had implicated him in the case.  Lindholm testified

further that Trenkler later told him that the government knew

that some of the  components used in the Roslindale  bomb had

been purchased locally and that, in response, Lindholm opined

that  the bomber had  been careless not  to have gone  out of

state.  To  this, Trenkler  agreed and then  stated that  the

local purchase was "regrettable."

          In addition,  Lindholm recalled  that at  one point

during the four  days they  discussed Trenkler's  involvement

with the 1986  Quincy bomb.  Lindholm  testified that, during

this discussion,  Trenkler asserted that  the Roslindale bomb

was much  more powerful than the  bomb he had built  in 1986.

                             -11-
                                          11


Ultimately, Lindholm stated  that Trenkler admitted  building

the Roslindale bomb, testifying that:

          [Lindholm:]    At  one point  he  stated,
          ["W]ell, even  if I  did build a  bomb, I
          did not place it on the car.["]

          [Government:]  What happened next?

          [Lindholm:]  Then he  paused for a moment
          and  said, ["S]o,  I built  the bomb.   I
          built the  bomb.  I don't  deserve to die
          or spend  the rest  of my life  in prison
          for building this device.["]

Lindholm  added further  that Trenkler  "stated that  the two

bomb  squad  officers  were  foolish and  negligent  for  not

wearing  body armor at the time that they were examining this

device, and in  essence that  it served them  right for  what

happened to them.  It wasn't his fault."  

          At  the   time  of  trial,  Lindholm   was  serving

sentences stemming  from convictions on federal  drug and tax

evasion charges.  Lindholm testified that he had not received

nor  discussed  receiving  anything  from  the  government in

return for  his testimony.  On  cross examination, Trenkler's

counsel  made  only a  minimal  effort  to impeach  Lindholm,

raising  matters  unrelated  to  his   testimony  implicating

Trenkler.     Primarily   Trenkler's  counsel   attempted  to

challenge Lindholm's  assertion that, as a small  boy, he had

at one  time lived on the same street as Trenkler and to show

that  Lindholm was  at  the Plymouth  House of  Correction in

December  1992  in  order   to  provide  information  to  the

                             -12-
                                          12


government  on  other  individuals  with  whom  he  had  been

involved in past criminal activities.

          In  addition to  Lindholm's  testimony, ATF  Agents

Dennis Leahy  and Thomas  D'Ambrosio recounted a  November 6,

1991, interview  they conducted  with Trenkler shortly  after

the  bombing.    During  this  interview,  Trenkler  admitted

building  the  Quincy bomb  and  sketched  a circuit  diagram

describing  it.   After making  the sketch,  Agent D'Ambrosio

asked Trenkler how the  diagram would differ if Trenkler  had

used dynamite like that  utilized in the Roslindale incident.

Both  agents testified  that, in  response to  this question,

Trenkler drew a second diagram,  which featured two sticks of

dynamite  connected to  two electrical  blasting caps.   Both

agents  added that  they  were surprised  when  they saw  the

diagram because the use of two electrical blasting caps was a

distinctive feature of  the Roslindale bomb that, at the time

of the interview, had not been disclosed  to the public.9  At

trial,  Leahy also  related other  conversations he  had with

Trenkler in  which Trenkler  conveyed a working  knowledge of

dynamite and electrical blasting caps.

          Leahy further testified  about a statement Trenkler

made to  him at the ATF  offices on February 4,  1992.  Leahy

                    
                                

9.  Although the  agents  conducted the  interview  during  a
search of Trenkler's place of business (to which Trenkler had
consented), neither agent attempted  to keep the drawing and,
consequently, it was not produced at trial.     

                             -13-
                                          13


explained  that Trenkler had come  to the offices  on his own

accord to pick up  previously-seized business records.  Leahy

stated that,  during his visit,  Trenkler engaged Leahy  in a

long  discussion,  lasting more  than  two  hours, about  the

course of the investigation.  According to Leahy's testimony,

after  Leahy had  ended  the  discussion, Trenkler  announced

arrogantly upon leaving the  ATF offices that "If we  did it,

then only we know about it.  How will you ever find out . . .

if neither one of us talk[]?"        

          The jury returned a guilty verdict on all counts of

the indictment.   Subsequently, the district  court sentenced

Trenkler  to concurrent  terms  of life  imprisonment on  the

counts  of  receipt  of  explosive  materials  and  attempted

malicious destruction of property  by means of explosives and

sixty months  on  the  count  of conspiracy.    Trenkler  now

appeals.    

                             II.
                                         II.
                                            

                          Discussion
                                      Discussion
                                                

          On appeal,  Trenkler assigns error to the admission

of the  Quincy bomb  evidence, contending primarily  that the

incident was not sufficiently  similar to the Roslindale bomb

to be relevant on the issue of identity, and to the admission

of the  EXIS  database-derived evidence  that the  government

used  to prove  the similarity  of the  two bombs.   Trenkler

additionally  argues  that  the  district  court  erroneously

                             -14-
                                          14


admitted several out-of-court statements made by Shay Jr.  We

discuss each argument in turn.10

A.  Quincy Bombing Evidence
                                       

          We   begin  with  Trenkler's  contention  that  the

district court erred in admitting  the evidence of the Quincy

bombing.

          1.  Fed. R. Evid. 404(b):  Other Act Evidence
                                                                   

          In  general,  Rule 404(b)11  proscribes the  use of

other bad-act evidence solely to establish that the defendant

has a  propensity towards  criminal behavior.   Rule 404(b)'s

proscription, however, is not absolute:  the rule permits the

                    
                                

10.  Trenkler   also  raises   the  issue   of  prosecutorial
misconduct.     Trenkler  contends   that  counsel  for   the
government  intentionally  made inflammatory  remarks  in the
government's  opening  statement  and  introduced  prohibited
other-act  evidence  in   contravention  of   representations
previously made to  the district court.  We find  no merit in
these contentions.   

11.  Fed. R. Evid. 404(b) provides:

          (b)  Other   Crimes,  Wrongs,   or  Acts.
          Evidence of other crimes, wrongs, or acts
          is not admissible  to prove the character
          of a  person in  order to show  action in
          conformity therewith.   It may,  however,
          be admissible for other purposes, such as
          proof  of  motive,  opportunity,  intent,
          preparation,  plan,  knowledge, identity,
          or  absence  of   mistake  or   accident,
          provided   that   upon  request   by  the
          accused,  the  prosecution in  a criminal
          case shall provide  reasonable notice  in
          advance of  trial, or during trial if the
          court  excuses  pretrial  notice on  good
          cause shown, of the general nature of any
          such evidence it intends to  introduce at
          trial.

                             -15-
                                          15


use of such evidence if it bears on a material  issue such as

motive,  knowledge or  identity.   In  this Circuit,  we have

adopted a two-part test  for determining the admissibility of

Rule 404(b)  evidence.  E.g., United States  v. Williams, 985
                                                                    

F.2d 634, 637  (1st Cir.  1993).  First,  the district  court

must  determine  whether  the   evidence  has  some  "special

relevance"  independent  of  its   tendency  simply  to  show

criminal propensity.  E.g., United  States v. Guyon, 27  F.3d
                                                               

723,  728 (1st  Cir.  1994).   Second,  if the  evidence  has

"special relevance" on a material issue,  the court must then

carefully conduct a  Rule 40312 analysis to determine  if the

probative  value  of  the   evidence  is  not   substantially

outweighed by the danger of unfair prejudice.  Williams,  985
                                                                   

F.2d  at 637.  As with most evidentiary rulings, the district

court has considerable leeway in determining whether to admit

or exclude Rule  404(b) evidence.  Accordingly, we review its

decision  only under the lens  of abuse of  discretion.  Id.;
                                                                        

see  also United  States v.  Fields, 871  F.2d 188,  196 (1st
                                               

Cir.), cert. denied, 493 U.S. 955 (1989).   
                               

                    
                                

12.  Fed. R. Evid. 403 provides:

          Although   relevant,   evidence  may   be
          excluded  if  its   probative  value   is
          substantially outweighed by the danger of
          unfair   prejudice,   confusion  of   the
          issues,  or  misleading the  jury,  or by
          considerations of undue  delay, waste  of
          time,   or   needless   presentation   of
          cumulative evidence.

                             -16-
                                          16


          2.  Identity
                                  

          The  government offered the  evidence of the Quincy

bomb, which  Trenkler admitted building,  primarily to  prove

that Trenkler also built the Roslindale bomb.  The government

contends that  the evidence of  the Quincy bomb  has "special

relevance"  on the  issue  of identity  because the  numerous

similarities  surrounding the Quincy and Roslindale incidents

compel  the conclusion  that the  same individual  built both

bombs.  Trenkler, on  the other hand, argues that  the Quincy

incident is too  dissimilar to  be relevant on  the issue  of

identity,  and even  if it  has some  relevance, the  risk of

unfair prejudice  that it  poses far outweighs  its probative

value.  We  agree with  the government that  the Quincy  bomb

evidence has "special relevance" on the issue of identity and

that  the  district  court  did not  abuse  its  considerable

discretion in admitting it.

               a.  Rule 404(b) Evidence:  Special Relevance
                                                                       

          When,  as in  this  case, Rule  404(b) evidence  is

offered because it  has "special relevance"  on the issue  of

identity, we have required, as a prerequisite to admission, a

showing that there exists a high degree of similarity between

the other  act and the charged  crime.  See United  States v.
                                                                      

Ingraham, 832 F.2d 229, 231-33 (1987), cert. denied, 486 U.S.
                                                               

1009 (1988).  Indeed, the proponent must demonstrate that the

two acts  exhibit a  commonality  of distinguishing  features

                             -17-
                                          17


sufficient  to  earmark them  as  the handiwork  of  the same

individual.   Id.  at  231.    This  preliminary  showing  is
                             

necessary because 

          [a] defendant cannot be identified as the
          perpetrator  of  the  charged act  simply
          because  he has at  other times committed
          the same commonplace variety  of criminal
          act except by  reference to the forbidden
          inference  of  propensity.   The question
          for  the  court[,  therefore,   must  be]
          whether  the characteristics  relied upon
          are sufficiently  idiosyncratic to permit
                                                     
          an inference of  pattern for purposes  of
          proof.

United States v. Pisari, 636 F.2d 855, 858-59 (1st Cir. 1981)
                                   

(internal quotations and citations omitted) (emphasis added).

          Resolving  whether the  prior  act is  sufficiently

similar to the charged offense to have "special relevance" on

the issue  of identity, however,  is essentially an  issue of

"preliminary"  or "conditional"  fact.   In other  words, the

prior act has no tendency to prove the perpetrator's identity

-- i.e., it is not relevant -- unless the proponent can first
                   

establish  the  conditional  fact:   that  the  two  acts are

sufficiently idiosyncratic to support the inference that they

are  the handiwork of the same individual.  The admissibility

of  evidence whose  relevance turns  on the  resolution of  a

conditional  fact is governed by  Fed. R. Evid.  104(b).  See
                                                                         

Huddleston  v. United States, 485 U.S. 681, 689 (1988).  Rule
                                        

104(b) provides, "When the relevancy of evidence depends upon

the fulfillment of a condition of fact, the court shall admit

                             -18-
                                          18


it  upon,  or  subject   to,  the  introduction  of  evidence

sufficient to  support a  finding of the  fulfillment of  the

condition."  Fed. R. Evid. 104(b).  Moreover,

          [i]n  determining whether  the Government
          has  introduced  sufficient  evidence  to
          meet Rule 104(b), the trial court neither
          weighs  credibility  nor makes  a finding
          that  the  Government   has  proved   the
          conditional  fact  by a  preponderance of
          the  evidence.  The court simply examines
          all  the evidence in the case and decides
          whether  the  jury could  reasonably find
          the  conditional   fact  .   .  .  by   a
          preponderance of the evidence.

Huddleston, 485  U.S. at 690.   Thus, as  here, when a  party
                      

seeks to  admit Rule  404(b) evidence to  establish identity,

the district court must condition  its admission on a showing

that the  shared characteristics  of  the other  act and  the

charged   offense  are  sufficiently   idiosyncratic  that  a

reasonable jury could find  it more likely than not  that the

same person performed them both.13  

                    
                                

13.  Huddleston involved  the use of Rule  404(b) evidence to
                           
prove knowledge in a case where the petitioner, charged  with
the knowing possession of stolen video tapes, claimed that he
did  not know the  tapes were stolen.   485 U.S.  at 683.  In
order to prove knowledge, the  government introduced evidence
of  the  petitioner's  previous   involvement  in  sales   of
allegedly stolen television sets.  The Supreme Court rejected
the   petitioner's  contention  that,  before  admitting  the
evidence,  the   district  court  was  required   to  make  a
preliminary finding  that the government had  proven that the
television sets were in fact stolen.  Id. at 687.
                                                     
          The Court stated that  "Rule 404(b) . . .  protects
against the introduction of  extrinsic act evidence when that
evidence  is  offered solely  to prove  character.   The text
contains no intimation, however, that any preliminary showing
is necessary  before such  evidence may be  introduced for  a
proper purpose."    Id.  at 687-88.    The  Court  continued,
                                   

                             -19-
                                          19


          Trenkler  contends that  the array  of similarities

between   the  two  incidents  amounts  to  no  more  than  a

collection of "prosaic commonalit[ies that] cannot give  rise

to an inference  that the  same person was  involved in  both

acts  without reference  to  propensity."   United States  v.
                                                                     

Garcia-Rosa, 876 F.2d 209, 225 (1st Cir. 1989), cert. denied,
                                                                        

493 U.S. 1030, cert. granted and vacated on other grounds sub
                                                                         

nom., Rivera-Feliciano v. United States, 498 U.S. 954 (1990).
                                                   

However,  in  resolving  whether  the  evidence  supports  an

inference   that  the   two   incidents   are   "sufficiently

idiosyncratic," we have cautioned that "an exact match is not

necessary."  Ingraham, 832 F.2d at 232.  The  test must focus
                                 

on  the  "totality  of   the  comparison,"  demanding  not  a

"facsimile or exact replica"  but rather the "`conjunction of

                    
                                

stating,  "If offered for such a proper purpose, the evidence
is subject  only to general strictures limiting admissibility
such as Rules 402 and 403."  Id. at 688.
                                            
          The Court  then stated  that evidence of  the prior
sales  was  relevant  for   the  proper  purpose  of  proving
knowledge only  if the jury  could find the  preliminary fact
that the televisions  were stolen.   Id. at 689.   Thus,  the
                                                    
Court held  that Rule 104(b) controlled  the admissibility of
the evidence.  Id.
                              
          Though   the  issue  here   arises  in  a  slightly
different  context, we  think  that  Huddleston provides  the
                                                           
appropriate framework for our analysis.  Here, the government
offered the Quincy bomb evidence  for the proper Rule  404(b)
purpose of identity.  The relevance of the Quincy bomb on the
issue of  identity turns, however, on the factual question of
whether   the  Roslindale   and  the   Quincy   bombings  are
sufficiently similar to earmark them as  the handiwork of the
same individual.  This is analogous to whether the television
sets in Huddleston were stolen, and, accordingly, Rule 104(b)
                              
sets the framework for admissibility. 

                             -20-
                                          20


several identifying characteristics  or the presence of  some
                                                   

highly distinctive quality.'"  Id. at 232-33 (quoting Pisari,
                                                                        

636  F.2d at 859) (emphasis added); see also United States v.
                                                                      

Myers,  550 F.2d 1036, 1045  (5th Cir. 1977)  ("[A] number of
                 

common  features of lesser  uniqueness, although insufficient

to  generate a  strong  inference of  identity if  considered

separately,  may  be  of  significant  probative  value  when

considered together.").  In this  case, we think the  balance

of  the  evidence  tilts  sufficiently  towards admission  to

satisfy  the   first  step  of  the   Rule  404(b)  analysis.

Accordingly, we believe that the district court did not abuse

its discretion  in determining that the numerous similarities

in components,  design, and  technique of  assembly, combined

with  the  similar  modus   operandi  and  the  closeness  of
                                                

geographic  proximity between  the  two events,  sufficiently

support the inference that the same person built both bombs.

          We begin by noting that the government's explosives

expert,  Thomas Waskom,  testified that  his analysis  of the

similarities shared by  the two  incidents left  him with  no

doubt "whatsoever" that the same individual built both bombs.

Our own review of  the record reveals that the  two bombs did

indeed   share   a   number   of   similar   components   and

characteristics.   Both bombs  were remote-controlled, radio-

activated, electronic explosive devices.  Both were  homemade

mechanisms,  comprising,  in  general, electronic  components

                             -21-
                                          21


easily  purchased at a hobby store.  Both had similar, though

not  identical,  firing  and  fusing  circuits with  separate

battery  power supplies for each.  Both had switches in their

fusing  circuits  to  disconnect  the radio  receivers.    To

energize  their  respective  radio  receivers,  both  devices

utilized  similar  power  supplies,  consisting  of  four  AA

batteries.   Both  employed many  similar components  such as

batteries,  duct  tape,  toggle  switches,  radio  receivers,

antennas,  solder, electrical tape,  and large  round speaker

magnets.   Moreover,  both used  a distinctive  method (i.e.,
                                                                        

twisting, soldering, and taping)  to connect some, though not

all,  of the  wires  used.14   Though we  hardly find  any of

these factors  by themselves to be  "highly distinctive," the

coalescence  of them  is fairly  persuasive.15   Indeed, even

                    
                                
14.  Though  it is unclear from a close reading of the record
just  how  many  of the  wires  in  each  bomb employed  this
connection method,  it is  apparent that  at least  some did.
More interestingly,  we note that, before  learning that both
bombs had wires that were joined in this fashion,  Trenkler's
explosives expert  stated that such a method is a "singularly
unique method[] of assembly  which individual bomb makers are
very likely to repeat."

15.  On the other hand,  Trenkler argues that the differences
between  the two  bombs are  more significant.   Some  of the
differences that Trenkler cites include: 

         Roslindale Bomb                   Quincy Bomb

 Two or three sticks of          Military flash simulator used
 dynamite rewrapped in a         which produced only minor
 magazine page and electrical    damage
 blasting caps which killed one
 officer and severely injured
 another                     -22-
                                          22


Trenkler's  expert  witness, Denny  Kline,  testified  at the

pretrial hearing that, in light of these similarities, "there

is  a  possibility, a  probability,  that  maybe there  is  a
                                                                         

connection between the maker of these two bombs."   (Emphasis
                      

added.)

          Moreover,  we note  that, in  refusing to  conclude

"beyond  a reasonable  doubt"16  that the  same person  built

both bombs, Trenkler's expert  Kline eschewed reliance on any

factors except  the physical evidence.   The appropriate test

for sufficient similarity, however, is not so limited.  "[I]n

assessing the sufficiency of  the evidence under Rule 104(b),

the trial court  must consider all evidence  presented to the
                                              

jury."  Huddleston, 485 U.S. at 690-91 (emphasis added).  
                              

          Accordingly,  we  believe   some  significance   is

properly attributed  to the  simple fact that  both incidents

                    
                                

 Futaba remote control system    Radio receiver taken from toy
 which used a small electrical   car
 servo motor                      
 "Single throw" toggle switch    Relay allowed power to be sent
 used to send power to dynamite  to explosives; "double throw"
                                 toggle switch used as safety

 Five nine-volt batteries        Two six-volt batteries
 provided power to firing        supplied power to firing
 system                          system

 Device was housed in a black    Device was wrapped in silver
 wooden box                      duct tape

16.  As the district court correctly noted in its ruling, the
government is not required  to establish "beyond a reasonable
doubt"  that  the  same person  built  the  two  bombs.   See
                                                                         
Huddleston, 485 U.S. at 690.
                      

                             -23-
                                          23


are  bombings.  A bombing, in  and of itself, is, arguably, a

fairly distinctive  method  for intimidating  or  killing  an

individual.  Cf. United States v. Patterson, 20 F.3d 809, 813
                                                       

(10th Cir. 1994)  (in a hijacking  case, uniqueness of  crime

itself has  significance in Rule 404(b) similarity analysis),

cert. denied, 115 S. Ct. 128 (1994);  Pisari, 636 F.2d at 858
                                                        

("[M]uch more  is demanded than the  mere repeated commission

of crimes of the  same class, such as repeated  burglaries or

thefts.  The device  used must be so unusual  and distinctive
                                                                         

as  to  be  like  a  signature."  (quotations  and  citations
                                          

omitted)).   In addition, both incidents  involved not simply

bombs, but remote-control bombs  that were placed  underneath

automotive vehicles.  

          In both  instances, the bombs were  constructed and

used to benefit a friend of the builder.  Trenkler  built the

Quincy bomb for Donna Shea to use to intimidate the owners of

the  Capeway  Fish Market,  and  the  evidence supported  the

inference that the person who constructed the Roslindale bomb

built  it  for   Shay  Jr.   to  use   against  his   father.

Furthermore,  in  both  instances the  builder  attempted  to

conceal  his or her participation  by using a  third party to

purchase  the  electronic components  used  in  the explosive

device.   In 1986, Trenkler initially waited in his car while

sending Donna Shea's nephew into the electronics store with a

list  to  purchase the  needed  components.   Similarly,  the

                             -24-
                                          24


evidence  supports  the inference  that  the  builder of  the

Roslindale  bomb  used  Shay   Jr.  to  purchase  the  needed

components.   Finally, the  fact that both  bombings occurred

within a relatively close  geographic proximity must be given

some weight in the analysis.  

          In United States v. Pisari, 636 F.2d 855  (1st Cir.
                                                

1981),  we reversed  the district  court's decision  to admit

evidence  of a prior robbery solely on the issue of identity,

where the  only similarity between it and the charged offense

was  that a knife was  used.  Similarly,  in Garcia-Rosa, 876
                                                                    

F.2d at 224-25,  we refused  to sanction the  admission of  a

prior drug  transaction where the only characteristic linking

it to  the charged drug deal was  the characteristic exchange

of a sample of drugs  prior to the sale.  In  Garcia-Rosa, we
                                                                     

held that a single "prosaic commonality" was insufficient "to

give rise to an  inference that the same person  was involved

in both acts without  reference to propensity."  Id.  at 225.
                                                                

See  also United States v. Benedetto, 571 F.2d 1246, 1259 (2d
                                                

Cir.  1978) (no  signature  where  shared  characteristic  is

merely  "a similar  technique for  receiving  the cash:   the

passing of folded bills by way of a handshake").  

          In   the  present  case,  however,  the  government

presented more than a  single "prosaic commonality."  Indeed,

the government  propounded a laundry list  of similarities in

design, component selection,  construction and overall  modus
                                                                         

                             -25-
                                          25


operandi.    On the  other  hand, Trenkler  offered  a fairly
                    

impressive list of differences between the two incidents.  In

the absence of one or more highly distinctive factors that in

themselves   point  to  idiosyncracy,  we  must  examine  the

combination  of all the factors.  Had Trenkler been unable to

point  to any  significant differences,  we suspect  he would

have had little chance in establishing an abuse of discretion

in  allowing the  evidence.   Similarly,  had the  government

found but  three or four common  characteristics to establish

sufficient  similarity, we  doubt that  the admission  of the

evidence  would have been granted or sustained.  Here, in the

middle,  with  substantial  evidence   on  either  side   and

conflicting  expert opinions,  could a  reasonable jury  have

found  it more  likely  than not  that  the same  person  was

responsible for both bombs?  We think the answer is yes.  See
                                                                         

Ingraham,  832 F.2d at  233 (admitting evidence)("[G]iven the
                    

host of  important comparables, the  discrepancies --  though

themselves  not  unimportant--  go   to  the  weight  of  the

challenged evidence, not to its admissibility.").17

                    
                                

17.  As we explain infra  in part II.A., we believe  that the
                                    
district court erred in  admitting the EXIS database evidence
on  the issue of idiosyncratic similarity.  Our review of the
record, however, convinces us that  the EXIS evidence did not
weigh  significantly in  the  court's decision  to admit  the
evidence of the Quincy bomb.  Cf. United States v.  Gallo, 20
                                                                     
F.3d  7, 14 (1st Cir. 1994) (abuse of discretion occurs when,
inter alia, improper factor is accorded significant weight).
                      

                             -26-
                                          26


               b.  Rule 404(b) Evidence:  Probative Value and
                                                                         

               Unfair Prejudice
                                           

          Resolving that the district court did not abuse its

discretion in  determining that  a rational jury  could infer

that it was more likely than  not that the same person  built

both bombs, however, does not end the analysis.  We must also

review  the trial  court's determination  that the  probative

value of the evidence was not substantially outweighed by the

risk of unfair prejudice.   Several factors weigh heavily  in

this  balancing,  such  as  the  government's  need  for  the

evidence,  see Fields, 871 F.2d at 198 (quoting Fed. R. Evid.
                                 

404(b) advisory committee's note),  the strength of  evidence

establishing the similarity of  the two acts, see Huddleston,
                                                                        

485 U.S. at 689 n.6, the inflammatory nature of the evidence,

and the degree to  which it would promote an  inference based

solely on  the  defendant's criminal  propensity, see  United
                                                                         

States v. Rubio-Estrada, 857 F.2d 845, 851-52 (Torruella, J.,
                                   

dissenting) (explaining inherent unfair prejudice in evidence

of prior bad acts).

          We believe the district court acted well within its

broad  discretion  in admitting  the  evidence.   First,  the

evidence  was  important  to  the  government's  case.    The

evidence that Trenkler had built the Quincy bomb corroborated

David  Lindholm's  testimony,  identifying  Trenkler  as  the

builder  of  the  Roslindale  bomb.    Second,  although  the

                             -27-
                                          27


evidence of  similarity could  have been more  compelling, it

was  nonetheless  substantial:    Indeed,   the  government's

explosives expert testified that he had no doubt "whatsoever"

that the same person designed and constructed both bombs.  

          On the  other hand,  we disagree with  the district

court  that  the evidence  did not  pose  any risk  of unfair

prejudice.18   As  with  all "bad  act"  evidence,  there  is

always some danger that the jury will use the evidence not on

the narrow point for which it is offered  but rather to infer

that  the   defendant  has  a   propensity  towards  criminal

behavior.   Nonetheless,  outside the context  of propensity,

the evidence  was not unduly  inflammatory.  The  Quincy bomb

did  not  kill or  injure  any individual  and  caused little

property damage.  Moreover,  the district court minimized any

risk of  unfair prejudice  by carefully instructing  the jury

not  to use  the  evidence of  the  Quincy bombing  to  infer

Trenkler's  guilt  simply  because  he was  a  bad  person or

because the  fact he had a built  a bomb in the  past made it

more likely he had built  the bomb in this case.   In sum, we

believe  that the district court did not abuse its discretion

in determining  that the probative  value of the  Quincy bomb

                    
                                

18.  In ruling  on the  evidence, the district  court stated,
inter alia, "The  evidence of  the [Quincy]  bomb is  without
                      
question prejudicial  in the sense  that it will  likely harm
the defendant.  That  is not the test, however,  the question
is whether it is unfairly prejudicial.  It is not."

                             -28-
                                          28


evidence  was not  substantially  outweighed by  the risk  of

unfair prejudice.19  

B.  EXIS Database Evidence
                                      

          Trenkler  contends that the district court erred in

admitting under the residual hearsay exception, Fed. R. Evid.

803(24),20  testimony about the results of  the search of the

                    
                                

19.  Trenkler also  contends that the  district court  abused
its discretion in admitting the Quincy bomb evidence to prove
knowledge,  skill, and intent.  With respect to the issues of
knowledge  and  skill, we  find  little  merit in  Trenkler's
argument.   Obviously, the fact that Trenkler had in the past
built a remote-control bomb has  some relevance on whether he
possessed  the skill  and  knowledge necessary  to build  the
Roslindale bomb.  See United States v. Latorre, 922 F.2d 1, 8
                                                          
(1st  Cir.   1990),  cert.  denied,  502   U.S.  876  (1991).
                                              
Furthermore, because the evidence was otherwise admissible to
show  identity, allowing  the government  to use  it to  show
skill  and  knowledge, posed  no  additional  risk of  unfair
prejudice.     Trenkler's contention with  respect to  intent
stands   on  firmer   ground.     We  have   some  difficulty
comprehending   (and   the   government   does   not  clearly
articulate) any theory of "special relevance" tending to show
intent that  does  not  depend  heavily on  an  inference  of
propensity.  See  United States  v. Lynn, 856  F.2d 430,  436
                                                    
(1st  Cir. 1988)  (error to  admit evidence  on  intent where
inference  depends on propensity).   Nonetheless, because the
evidence was  properly admitted  to show  identity, knowledge
and  skill,  any error  in its  admission  to show  intent is
harmless.   See  Benavente Gomez,  921 F.2d at  386 (harmless
                                            
error if it is "highly probable" the error did not contribute
to the verdict).

20.  Fed. R. Evid. 803 provides:

          The  following are  not  excluded by  the
          hearsay rule, even  though the  declarant
          is available as a witness:
          . . .
          (24) Other Exceptions
                      (24) Other Exceptions
               A statement not specifically covered
          by  any of  the foregoing  exceptions but
          having      equivalent     circumstantial
          guarantees  of  trustworthiness,  if  the

                             -29-
                                          29


EXIS database.   He maintains that  the district court  erred

because  the underlying reports  composing the  EXIS database

lack sufficient guarantees of trustworthiness to fall  within

the residual  hearsay exception.  We agree  that the district

court erred  in admitting  the evidence,  but find  the error

harmless.

          The government offered  the EXIS-derived  testimony

as tending  to  show that  the  Roslindale and  Quincy  bombs

evinced the  signature of a single bomb maker.  Specifically,

the government  offered it as an  affirmative assertion that,

out  of  more  than  14,000  bombing  and  attempted  bombing

incidents,  only the  Roslindale  and  the  Quincy  incidents

possessed in common all of the queried characteristics.   The

district court admitted the  EXIS-derived testimony under the

                    
                                

          court determines that  (A) the  statement
          is  offered as  evidence  of  a  material
          fact; (B) the statement is more probative
          on the point for which it is offered than
          any  other  evidence which  the proponent
          can  procure through  reasonable efforts;
          and (C)  the  general purposes  of  these
          rules and the  interests of justice  will
          best  be  served   by  admission  of  the
          statement  into  evidence.    However,  a
          statement  may not be admitted under this
          exception  unless  the  proponent  of  it
          makes   known   to   the  adverse   party
          sufficiently in advance  of the trial  or
          hearing to provide the adverse party with
          a fair opportunity to prepare to meet it,
          the  proponent's  intention to  offer the
          statement  and  the  particulars  of  it,
          including the  name  and address  of  the
          declarant.

                             -30-
                                          30


residual hearsay exception, finding that it was "sufficiently

reliable."  In reaching this conclusion, the court noted that

the  EXIS  database   was  used  and  relied   upon  "by  law

enforcement authorities on a  regular basis."  The government

asserts  that the district court did not err in admitting the

testimony because,  in general,  the underlying  reports were

"written  objective  reports" summarizing  careful  field and

laboratory  investigations that  the court  could permissibly

find  to   be  particularly   worthy  of  belief   such  that

"adversarialtesting ... wouldaddlittle to[their]reliability."

          Initially,  it  is  evident  that  whether  or  not

particular  evidence  may  be  admitted  under  the  residual

hearsay exception is a fact-specific inquiry committed in the

first instance to the sound discretion of the district court.

United  States v.  Doe, 860  F.2d 488,  491 (1st  Cir. 1988),
                                  

cert.  denied,  490  U.S.  1049  (1989).    We  accord  great
                         

deference to the district court's determination, reviewing it

only  for an  abuse of  discretion.   E.g., United  States v.
                                                                      

Benavente  Gomez,   921  F.2d  378,  384   (1st  Cir.  1990).
                            

Nevertheless,   we   will   overturn   a   district   court's

determination if,  upon careful  review, we  are left  with a

"definite  and firm  conviction that the  court made  a clear

error of  judgment" in its  decision to admit  the testimony.

Id. (internal quotations and citations omitted).
               

                             -31-
                                          31


          Under  the residual hearsay exception, the district

court  must  determine,  inter  alia,  whether the  proffered
                                                

evidence    possesses     "circumstantial    guarantees    of

trustworthiness" equivalent to  those possessed by  the other

listed exceptions to  the hearsay  rule.  See  Fed. R.  Evid.
                                                         

803(24); Polansky v.  CNA Ins.  Co., 852 F.2d  626, 631  (1st
                                               

Cir.  1988);  cf. 2  Kenneth S.  Broun  et al.,  McCormack on
                                                                         

Evidence   324,  at 362  (John W. Strong  ed., 4th ed.  1992)
                    

(equivalent  guarantees   of  trustworthiness  is   the  most

important issue).   This trustworthiness  inquiry is  largely

fact driven, and its focus will vary depending on the context

in which the issue  arises.  See Brookover v.  Mary Hitchcock
                                                                         

Memorial Hosp.,  893 F.2d 411, 420 (1st Cir. 1990).  A court,
                         

however, may consider whether the evidence shares reliability

factors (e.g.,  personal knowledge,  lack of bias)  common to

the  other hearsay exceptions, see 2 McCormack   324, at 362-
                                                          

4,  and whether the  evidence, but for  a technicality, would

otherwise come within a specific exception, see United States
                                                                         

v.  Nivica,  887 F.2d  1110, 1126-27  (1st Cir.  1989) (where
                      

insufficient foundation  laid  to admit  financial  documents

under  business records  exception, court  had discretion  to

admit them under residual  exception), cert. denied, 494 U.S.
                                                               

1005 (1990).  Essentially,  the district court must determine

whether  the totality  of  the circumstances  surrounding the

statement  establish its  reliability sufficiently  enough to

                             -32-
                                          32


justify  foregoing  the rigors  of in-court  testimony (e.g.,

live testimony under oath, cross-examination) that ordinarily

guarantee trustworthiness.   See Michael  H. Graham,  Federal
                                                                         

Practice and  Procedure:  Evidence,   6775,  at 737-40 (1992)
                                              

(courts employ  "ad hoc assessment of  reliability based upon

the totality  of the surrounding circumstances");  cf. United
                                                                         

States v. Ellis, 935  F.2d 385, 394 (1st Cir.)  (citing Idaho
                                                                         

v.  Wright,   497  U.S.  805,  819   (1990))  (guarantees  of
                      

trustworthiness  in  Confrontation  Clause  context  must  be

established  from the "totality of circumstances" surrounding

the  making of  the statement),  cert.  denied, 502  U.S. 869
                                                          

(1991).

          Because  we believe  that  the  government  clearly

failed to establish that  the EXIS-derived evidence possessed

sufficient "circumstantial guarantees of trustworthiness," we

hold  that  the  district  court  abused  its  discretion  in

admitting the evidence.  As  noted above, the district  court

rested its decision to admit the testimony, at least in part,

on its finding that law-enforcement agencies  use and rely on

the database "on a regular  basis."  Though we take no  issue

with this  narrow finding,  it is  hardly dispositive  on the

issue of trustworthiness.   That law enforcement  authorities

rely  on information  culled from  the database  does not,  a
                                                                         

fortiori, imbue  that information with  sufficient guarantees
                    

of trustworthiness to  warrant admission under  Rule 803(24).

                             -33-
                                          33


Indeed, law enforcement authorities often rely on information

during  their  investigations (e.g.,  polygraph examinations,

anonymous tips)  that would not necessarily  be admissible as

evidence.  See  United States v.  Scarborough, 43 F.3d  1021,
                                                         

1026  (6th  Cir.  1994)  (polygraph   examinations  generally

inadmissible); and Fed R. Evid. 801, 802 (prohibiting hearsay
                              

evidence).  

          More  to  the  point,  the   government  failed  to

establish that the reports underlying the  database possessed

any guarantees  of trustworthiness similar to  those found in

the  enumerated hearsay  exceptions.   See generally  Fed. R.
                                                                

Evid. 803(1)-(23).  Scheid,  the government's expert on EXIS,

stated that the database derived from reports submitted by  a

variety of federal, state and local law enforcement agencies.

Though Scheid testified extensively on the reliability of the

procedures he  followed to cull information  from the reports

and  subsequently  input  it  into  the  EXIS  database,  the

government   offered   virtually  nothing   establishing  the

reliability of the underlying reports.  

          On  cross-examination, Scheid, who  had been solely

responsible  for EXIS  since  1977, admitted  that no  agency

outside of the ATF was required by law to send reports to the

EXIS database  and that  state and local  agencies submitting

reports were not required to follow any express procedures or

conform to any specific  standards in collecting or recording

                             -34-
                                          34


the reported information.   Indeed, it is far from  clear the

extent  to  which  information  memorialized in  any  of  the

reports  derives  from   laboratory  analyses,   on-the-scene

observations  of police officers, second-hand descriptions of

the device by layperson witnesses, or some other source.  Cf.
                                                                         

United  States v. Scholle, 553 F.2d  1109, 1123-25 (8th Cir.)
                                     

(allowing  printouts  from  Drug  Enforcement  Administration

("DEA")  computer  database  where  database  comprised  only

chemical  analyses performed  at regional  DEA laboratories),

cert. denied, 434 U.S. 940 (1977). 
                        

          Scheid further testified that the submitted reports

need not be signed, and that nothing required the author of a

submitted report to have  personal knowledge of its contents,

see  Fed.  R. Evid.  803  advisory  committee's note  ("In  a
               

hearsay situation,  the declarant  is, of course,  a witness,

and  neither  this rule  nor  Rule  804  dispenses  with  the

requirement of  firsthand knowledge."); Fed.  R. Evid. 803(6)

(business  record must  be  recorded by  or from  information

supplied by  an individual  with personal knowledge),  or for

that matter  to  be qualified  as  a bomb  investigator,  see
                                                                         

Mathews v. Ashland  Chem., Inc., 770 F.2d  1303, 1309-10 (5th
                                           

Cir. 1985); 4 Jack B. Weinstein et al., Weinstein's Evidence,
                                                                        

  803(8)[03], at 803-283  ("Questions of the qualification of

the  expert  can  be  raised  as  one  of  the  circumstances

indicating  lack  of trustworthiness.");  cf.  Beech Aircraft
                                                                         

                             -35-
                                          35


Corp.   v.   Rainey,   488   U.S.  153,   167   n.11   (1988)
                               

("investigator's skill or experience" is  factor establishing

trustworthiness of  government evaluative report).   Finally,

Scheid admitted that he  employed no procedures for verifying

or updating  information in the  EXIS database that  had been

submitted by agencies other than ATF.

          The underlying reports,  arguably, come closest  to

falling within  the hearsay exception for  public records and

reports, Fed. R. Evid.  803(8).  In criminal cases,  however,

Rule  803(8)  does not  authorize  the  prosecution's use  of

investigative  reports  that  contain  "matters  observed  by

police officers  and other law enforcement  personnel,"  Fed.

R. Evid.  803(8)(B), or  "factual findings resulting  from an

investigation made pursuant to  an authority granted by law,"

Fed. R. Evid. 803(8)(C).  See United States v. Arias-Santana,
                                                                        

964  F.2d 1262, 1264 (1st  Cir. 1992) (police reports offered

by prosecution generally inadmissible); but cf., e.g., United
                                                                         

States  v. Brown, 9 F.3d  907, 911-12 (11th  Cir. 1993) (Rule
                            

803(8)  does  not  necessarily  prohibit the  use  of  police

records prepared in a routine non-adversarial setting that do

not  result from  subjective  investigation and  evaluation),

cert. denied, 115 S. Ct. 152 (1994).  Moreover, the exception
                        

provided by  Rule 803(8)  is further  limited by  the general

qualification proscribing  the use of public  records if "the

                             -36-
                                          36


sources of information or other circumstances indicate a lack

of trustworthiness."  Fed. R. Evid. 803(8).     

          We have  noted that Congress  intended the residual

hearsay  exception  to be  used  "`very rarely,  and  only in

exceptional circumstances.'"   Benavente  Gomez, 921 F.2d  at
                                                           

384 (quoting S. Rep. No. 1277, 93d Cong. 2d Sess., 20 (1974),

reprinted in 1974 U.S.C.C.A.N.  7051, 7066); see also Nivica,
                                                                        

887 F.2d at 1127 ("Rule 803(24) should  be used stintingly").

Moreover,  Congress did  not  intend for  the exception  "`to

establish a broad license  for trial judges to  admit hearsay

statements   that  do  not  fall  within  one  of  the  other

exceptions' or `to authorize  major judicial revisions of the

hearsay rule.'"  Benavente Gomez, 921 F.2d at 384 (quoting S.
                                            

Rep.  No. 127).    In this  case,  the government  failed  to

establish  that  the  reports  composing  the  EXIS  database

possessed  guarantees  of trustworthiness  equivalent  to the

other  exceptions  to  the  hearsay  rule.   Neither  are  we

convinced  that the totality of circumstances surrounding the

reports   adequately  assure   their  reliability   where  no

standardized procedures were employed in creating the reports

and  the sources  of  the reported  information are  unknown.

Finally, we find it significant that the government points us

to no case  in which it has  successfully (or unsuccessfully)

sought to  admit EXIS-derived evidence to  prove the identity

of  a bomb  maker.   Accordingly, we  hold that  the district

                             -37-
                                          37


court  abused  its discretion  in admitting  the EXIS-derived

evidence  under the residual exception to the hearsay rule to

prove the identity of the builder of the Roslindale bomb.21

                    
                                

21.  Even putting aside our concerns about the reliability of
the underlying  reports,  we  remain,  in  general,  somewhat
troubled  by  the government's  use  of  the evidence.    The
statement that out of more than  14,000 bombing and attempted
bombing incidents  in the  EXIS database only  the Roslindale
and  Quincy  incidents  share   the  eight  specific  queried
characteristics  (bombings  and attempted  bombings, attached
under car or truck, remote-control, round magnets, duct tape,
solder, AA  batteries, toggle switches) is  a fairly powerful
statement, but perhaps a somewhat misleading one.
          First,  the   statement  assumes  as   a  necessary
predicate  that each  of the  more than  14,000 EXIS  entries
definitively  states  whether  or not  the  explosive  device
described therein actually  possessed those  characteristics.
We  have some doubt about the validity of such an assumption.
In  general,  bomb  reconstruction  strikes us  as  a  rather
resource-intensive operation.   We can envision circumstances
(e.g., a blast  causing little  or no injuries  or damage,  a
                 
bomb  maker  apprehended before  reconstruction investigation
complete) where  the investigation  and the  resulting report
might not be nearly as thorough or complete as in the case of
                 
either the Roslindale  or the Quincy  bombs.  Indeed,  during
the preliminary  hearing both  Scheid and Thomas  Waskom, the
government's explosives expert, acknowledged that the absence
of an item, such  as magnets or batteries, from  a post-blast
report  meant  only that  investigators  did  not recover  or
identify the item and not that it was not used.
          Second, without further statistical analysis of the
database, we  believe the  statement that  out  of more  than
14,000 incidents  only the Quincy and  Roslindale bombs share
the  eight queried characteristics is potentially incomplete.
For  example, by our count,  the EXIS database  entry for the
Roslindale    incident    lists   approximately    twenty-two
characteristics  describing that  incident.   Nowhere in  the
record, however, does the government  explain why it chose to
focus  on  the specific  characteristics  used  to query  the
database.  It does not suggest that these characteristics are
more important in a  bomb-signature analysis than any of  the
other characteristics not chosen.   Moreover, the  government
does not offer any  analysis of the significance of  the fact
that  the  Roslindale  and  the Quincy  incidents  share  the
queried characteristics.   In other words, though it  is true
that  only  the  Quincy  incident shares  the  eight  queried

                             -38-
                                          38


          Although we agree  with Trenkler that the  district

court  erred  in  admitting  the  EXIS-derived  evidence,  we

nonetheless  find  the  error  harmless  beyond  a reasonable

doubt.22    Initially  we  note  that  substantial  evidence,

beyond  Trenkler's  participation  in  the   Quincy  bombing,

supported a  finding that he  had built the  Roslindale bomb.

Principally, David Lindholm  convincingly testified that,  in

fact, Trenkler had actually admitted  building the Roslindale

bomb.   Other  admissions  by Trenkler  made  to various  law

                    
                                

characteristics with the Roslindale  incident, how many other
incidents  share some other set of eight (or more than eight)
characteristics with the Roslindale incident?  
          Arguably, these  concerns go more to  the weight of
the evidence  than to its  admissibility.  However,  we point
them out  here  to underscore  the caution  a district  court
should  employ  in  allowing  evidence couched  in  terms  of
numerical probabilities.   Cf.  United States v.  Massey, 594
                                                                    
F.2d  676,   679-81  (8th  Cir.   1979)  (testimony   stating
probability  of  match to  be  one chance  in  4,500 unfairly
confusing where no foundation for statement provided). 

22.  In  general, we  review an  evidentiary miscue  only for
harmless error,  dismissing it  if "we  determine that  it is
highly probable  that  the error  did not  contribute to  the
verdict."    Benavente  Gomez,  921  F.2d  at  386  (internal
                                         
quotations and  citations omitted).   In this  case, however,
Trenkler also contends that the erroneously admitted evidence
deprived  him of  his  confrontation rights  under the  Sixth
Amendment,  see  U.S.  Const.  amend  VI  ("In  all  criminal
                           
prosecutions, the accused  shall enjoy the right . .  . to be
confronted  with  the  witnesses against  him.").    Assuming
arguendo  that the  admission  of the  EXIS-derived  evidence
                    
rises to  the level  of constitutional error,  we accordingly
employ a  stricter standard,  asking whether we  can consider
the  error harmless  beyond a  reasonable doubt.   See United
                                                                         
States v.  Brennan, 994 F.2d 918,  927 (1st Cir. 1993);   see
                                                                         
also United States  v. Argentine, 814  F.2d 783, 788-89  (1st
                                            
Cir.  1987) (constitutional  errors  may not  be regarded  as
harmless  if there is a reasonable possibility that the error
influenced the jury in reaching a verdict).

                             -39-
                                          39


enforcement  officers  inferentially corroborated  Lindholm's

testimony,  specifically Trenkler's sketch  of the Roslindale

bomb,  drawn shortly  after  the explosion  and conspicuously

featuring two electrical blasting caps.  Moreover, Trenkler's

arrogant assertion to Agent  Leahy that, "if we did  it, then

only we know about it . . . how will you ever find out . .  .

if neither one of us talk[]?" provided further corroboration.

Additional support could be  inferred from the ample evidence

the government adduced  establishing Trenkler's  relationship

withShayJr.and hisknowledgeofbothelectronics andexplosives.23

          Furthermore,  the  government  offered   the  EXIS-

derived  evidence to  prove  that the  Roslindale and  Quincy

bombs  were so similar that  they evinced the  signature of a

single bomb  maker, thus,  establishing the relevance  of the

Quincy bomb evidence on the issue of identity.  Our review of

the  record,  however,  convinces  us  that the  EXIS-derived

evidence  was not a  critical factor in  the district court's

decision to admit the Quincy bomb evidence for the purpose of

proving  identity.   The  EXIS-derived  evidence  was  merely

cumulative,  corroborating the testimony  of the government's

explosives expert  who, after testifying in  detail about the

                    
                                

23.  We note  with some  concern  our dissenting  colleague's
suggestion   that,   notwithstanding   Lindholm's   testimony
(elicited by the  U.S. Attorney) that the  government had not
offered  or  promised  Lindholm  any  consideration  for  his
testimony, an  implicit quid pro quo  nonetheless existed for
                                                
his cooperation.  See infra  at 65 n.43.  We find  nothing in
                                       
the record to support such an inference.

                             -40-
                                          40


similarities between the  two bombs,  stated that  he had  no

doubt "whatsoever"  that the same person  built both bombs.24

Moreover, as  discussed supra at  20-26, other circumstantial
                                         

evidence tending  to show that the maker  of each bomb used a

similar modus operandi (e.g., both  bombs built for a friend,
                                        

both  bomb   makers  used  third  party   to  acquire  needed

components)  independently supported  the inference  that the

same  person built both  bombs.  Finally,  even putting aside

whether  the   jury  would  have  found   the  two  incidents

sufficiently  similar to  prove  identity without  the  EXIS-

derived evidence,  the jury nonetheless would  have been able

to consider the fact that Trenkler had designed and built the

Quincy bomb to prove Trenkler's knowledge and skill.

          In  sum, while  the admission  of the  EXIS-derived

evidence would not have been harmless error if the only other

evidence consisted of the expert's testimony of signature and

the  evidence establishing Trenkler's  relationship with Shay

Jr. and  his electrical and explosive  skills, the additional

                    
                                

24.  Our dissenting colleague correctly notes that, in ruling
on the  admission of the  Quincy bomb evidence,  the district
court stated that it was "adding" the statistical evidence to
the expert's testimony.   But we  differ from his  conclusion
that  it is  "plain" that  the district  court relied  on the
EXIS-derived  evidence  to  form  "the  critical  final  link
between  the  two devices,"  see infra  at  55.   Indeed, the
                                                  
court's discussion focuses entirely on  the expert testimony,
with  only the  passing  reference at  the  end to  the  EXIS
system.   In this  context, we read the  district court to be
saying not  that  the  EXIS  evidence was  necessary  to  its
                                                                
decision, but  only that  it provided additional  support for
it.

                             -41-
                                          41


presence  of  several different  strong sources  of testimony

relating Trenkler's admissions, convinces us that no rational

jury could have entertained  a reasonable doubt of Trenkler's

guilt even in the absence of the EXIS-derived evidence.25

C.  Shay Jr.'s Out-of-Court Statements
                                                  

          Trenkler  additionally  asserts  that the  district

court erred by admitting  testimony relating ten out-of-court

statements purportedly  uttered by Shay Jr.   The statements,

in general, tended to  implicate Shay Jr. in the  bombing and

to suggest that Shay  Jr. had not acted alone.   The district

court admitted the  statements either as  nonhearsay evidence

of Shay  Jr.'s state of  mind, see  Fed. R.  Evid. 801(c);  2
                                              

McCormack   269 at 208, or as falling within the declaration-
                     

against-penal-interest exception  to  the hearsay  rule,  see
                                                                         

Fed. R. Evid. 804(b)(3).  Trenkler argues that  the admission

of  these   statements   violated  his   rights   under   the

Confrontation Clause.26  We do not agree.

                    
                                

25.  We agree with our dissenting brother that we may find an
error harmless beyond a reasonable  doubt only when the other
evidence in the case, "standing alone, provides `overwhelming
evidence'  of  the  defendant's  guilt."    See  infra at  53
                                                                  
(quoting Clark v. Morgan,  942 F.2d 24, 27 (1st  Cir. 1991)).
                                    
In  contrast with  our colleague,  however, we  believe that,
when the  evidence of Trenkler's participation  in the Quincy
bombing, which we do not believe was rendered inadmissible by
the admission  of the EXIS-derived evidence, is  added to the
"substantial"  other   evidence  of  Trenkler's   guilt,  the
resulting sum is clearly "overwhelming."

26.  We  do  not  understand  Trenkler  to  assert  that  the
district  court committed  error under  the Federal  Rules of
Evidence in  admitting the statements.   Though Trenkler does

                             -42-
                                          42


          In  asserting  a  Confrontation  Clause  violation,

Trenkler  relies primarily  on Bruton  v. United  States, 391
                                                                    

U.S. 123 (1968),  in which the Supreme Court held  that, in a

joint trial,  an instruction  to  the jury  to disregard  the

confession  of one non-testifying  defendant was insufficient

to prevent the confession from unfairly prejudicing the other

defendant.   Critical to the  Bruton Court's decision was the
                                                

trial  court's  undisputed  ruling  that the  confession  was

inadmissible  against the non-confessing  defendant.   Id. at
                                                                      

128  n.3.   Bruton has  no application  in the  present case,
                              

however, because the challenged statements here were directly

admissible against Trenkler and,  consequently, did not  pose

the Bruton risk of  spill-over prejudice.  In this  case, the
                      

district court  admitted the  statements against  Trenkler to

establish the existence of the conspiracy.  

          The Confrontation Clause does not proscribe the use

of  all out-of-court statements.   See  Idaho v.  Wright, 497
                                                                    

U.S. 805, 813 (1990).   In general, nonhearsay statements  or

statements  not  offered to  prove  the truth  of  the matter

asserted   do  not   raise  Confrontation   Clause  concerns.

Tennessee v. Street, 471 U.S.  409, 414 (1985); United States
                                                                         

v. Levine, 5 F.3d  1100, 1107 (7th Cir. 1993),  cert. denied,
                                                                        

                    
                                

state at  one point  that the declarations  "were erroneously
admitted  .  .  .  as  statements  against  Shay Jr.'s  penal
interest or of Shay Jr.'s state of mind," he does not explain
this assertion of error except on constitutional grounds. 

                             -43-
                                          43


114 S. Ct. 1224  (1994).  Moreover, the  Confrontation Clause

does not  necessarily prohibit the use  of hearsay statements

where  the  trial  court  has admitted  them  pursuant  to  a

"firmly-rooted"  exception  to   the  hearsay  rule   or  has

otherwise found  the  statements to  possess  "particularized

guarantees of trustworthiness."  See Wright, 497 U.S.  at 816
                                                       

(citing Ohio v. Roberts, 448 U.S. 56, 66 (1980)).
                                   

          To the extent that  the district court admitted the

statements as nonhearsay  evidence, Trenkler's  Confrontation

Clause challenge lacks merit.   See Street, 471 U.S.  at 414.
                                                      

As for the  rest, we have strongly suggested  previously that

the exception  for declarations  against penal interest  is a

"firmly rooted" exception  to the hearsay  rule.  See  United
                                                                         

States v. Seeley, 892  F.2d 1, 2 (1st Cir.  1989) ("exception
                            

for  declarations against  penal  interest would  seem to  be

`firmly   rooted'").    Trenkler   does  not  challenge  this

assumption,  nor  does  he  explain  why  the  statements  in

question lack "particularized guarantees of trustworthiness."

Accordingly,  we are  not persuaded  that the  district court

violated Trenkler's confrontation rights by admitting them.

                             III.
                                         III.
                                             

                          Conclusion
                                      Conclusion
                                                

          For the  foregoing  reasons, we  affirm  Trenkler's

conviction.

                             -44-
                                          44


                              Dissent follows.
                                          Dissent follows.

                             -45-
                                          45


          TORRUELLA, Chief Judge, (Dissenting).   In my view,
                      TORRUELLA, Chief Judge, (Dissenting).
                                            

the erroneous admission in this case of evidence derived from

the  EXIS computer  database  violated the  defendant's Sixth

Amendment right to confront  witnesses against him.  Contrary

to my brethren, I do not believe that this error was harmless

beyond a reasonable doubt.  I therefore dissent.

                              I.
                                          I.
                                            

          Trenkler   admitted  to  building   a  device  that

exploded  in  Quincy  in  1986.    The  government's  central

strategy at trial27 was  to prove that the Quincy  device was

so similar to the Roslindale bomb  that they had to have been

built by  the same person.   Stephen Scheid,  an Intelligence

Research Specialist  with the Bureau of  Alcohol, Tobacco and

Firearms  ("ATF"), testified  that  he  conducted a  computer

query  on   the  ATF's  EXIS  database28   to  identify  bomb

incidents  which  shared  certain  characteristics  with  the

Roslindale incident.  Based on this analysis, Scheid told the

jury that,  out of the 14,252 bombings and attempted bombings

reported  in  EXIS,  only   the  Roslindale  and  the  Quincy

incidents shared all the queried characteristics.

          For a jury  reviewing otherwise weak circumstantial

evidence of  defendant's guilt (see infra),  this is powerful
                                                     

                    
                                

27.  In  support of its motion in limine to admit evidence of
the 1986 incident, the  government described this evidence as
"the centerpiece of the Government's case in chief."

28.  For a description of the EXIS database, see supra p. 8.
                                                                  

                             -46-
                                          46


stuff  --  tangible,  "scientific"  evidence which  seems  to

conclusively  establish that  the  same person  who made  the

Quincy  device in  1986  made the  Roslindale  bomb in  1991.

Unfortunately, as  the majority  concedes,  the reports  from

which the EXIS information is derived are utterly unreliable,

thus  rendering its  conclusion equally  unreliable, and,  as

will  be shown,  completely  misleading.   For three  related

reasons,  I  disagree  with  the majority's  conclusion  that

admission of the EXIS-derived  evidence  was "harmless beyond

a  reasonable  doubt."    First,  the  EXIS-derived  evidence

plainly influenced the district court's decision to allow the

government's motion to admit evidence of the Quincy incident,

under Fed. R. Evid. 404(b), to show that the same person must

have  built the  Roslindale bomb.   Second,  the EXIS-derived

evidence  was very powerful and very  misleading.  Third, the
                                                

other evidence against Trenkler was not "overwhelming," as is

required under our precedent.

                             II.
                                         II.
                                            

          The  majority  assumes,   without  deciding,   that

Trenkler's  Sixth  Amendment  right  to   confront  witnesses

against him was violated  by introduction of the EXIS-derived

evidence.     Supra  n.22.    As   the  majority  recognizes,
                               

constitutional cases  are  governed by  a stringent  harmless

error analysis -- a conviction cannot stand unless the effect

of  the evidence  is  "harmless beyond  a reasonable  doubt."
                                                                       

                             -47-
                                          47


Chapman  v.  California, 386  U.S.  18,  24 (1966)  (emphasis
                                   

added); United  States v.  De Jes s-R os, 990  F.2d 672,  678
                                                    

(1st  Cir.  1993).29   To  comprehend  why admission  of  the

EXIS-derived  evidence was  not harmless beyond  a reasonable

doubt,  one must  understand  the nature  and  extent of  the

constitutional  violation.     Because  the  majority  barely

acknowledges, much less  discusses, the constitutional  right

at stake in this case,  its result appears both  analytically

sound and benign.  It is  neither.  I will therefore begin by

explaining  why,   and  to  what   extent,  Trenkler's  Sixth

Amendment   right  to  confront  witnesses  against  him  was

violated.  I will then endeavor to show why this error cannot

be considered harmless.

                             III.
                                         III.
                                             

          The  Confrontation Clause  of  the Sixth  Amendment

provides  that, "[i]n all  criminal prosecutions, the accused

shall  enjoy  the right  .  .  . to  be  confronted  with the

witnesses against him."  The Supreme Court has explained that

"[t]he  central concern  of  the Confrontation  Clause is  to

ensure  the reliability  of the  evidence against  a criminal

defendant by subjecting it to rigorous testing in the context

                    
                                

29.  Under  the standard  for analyzing  harmless error  in a
non-constitutional case, the court  will uphold a  conviction
provided  it  can  be  said  "that   the  judgement  was  not
substantially swayed by the error."  United States v. Flores,
                                                                        
968 F.2d 1366, 1372 n.7 (1st Cir. 1992) (quoting Kotteakos v.
                                                                      
United States, 328 U.S. 750, 765 (1946)). 
                         

                             -48-
                                          48


of  an  adversary  proceeding  before  the  trier  of  fact."

Maryland v. Craig, 497 U.S. 836, 845 (1990); United States v.
                                                                      

Zannino, 895 F.2d  1, 5 (1st Cir. 1990) ("the  mission of the
                   

Confrontation Clause  is to  advance a practical  concern for

the  accuracy of  the truth-determining  process  in criminal

trials  by assuring that the trier of fact has a satisfactory

basis  for  evaluating the  truth  of  the prior  statement")

(quoting Dutton v. Evans, 400  U.S. 74, 89 (1970)  (plurality
                                    

opinion)).

          Hearsay  evidence  from an  unavailable declarant30

may only be admitted  against a defendant in a  criminal case

if the government can demonstrate that the proffered evidence

"bears adequate  indicia of  reliability."  Ohio  v. Roberts,
                                                                        

448   U.S.   56,   66  (1980)   (internal   quotation   marks

omitted).31    The  government  may satisfy  this  burden  by

                    
                                

30.  For practical  purposes, the authors of  the over 14,000
underlying  EXIS reports  were  effectively "unavailable"  in
this case.   See United  States v. Inadi,  475 U.S. 387,  394
                                                    
(1986) (absolute unavailability not constitutionally required
in  all cases); Manocchio v. Moran, 919 F.2d 770, 774-76 (1st
                                              
Cir. 1990) (same).  

31.  The  majority  properly   holds  that  the  EXIS-derived
statement  --  that out  of  more  than  14,000 bombings  and
attempted bombings  in the EXIS database  only the Roslindale
and   Quincy   incidents    shared   the   specific   queried
characteristics -- is inadmissible  totem pole hearsay.  That
is,  it was based on  a host of  out-of-court statements (the
14,252  underlying  reports  submitted  by  unknown  authors)
offered  in  court for  the  truth  of the  matters  asserted
therein (the characteristics of those bombings).  See Fed. R.
                                                                 
Evid.  801.   Because  we know  neither  who submitted  those
underlying reports,  nor under what  conditions, the majority
properly  holds that the statements do not satisfy any of the

                             -49-
                                          49


establishing either that the  evidence "falls within a firmly

rooted  hearsay exception"  or by  showing that  the evidence

possesses  "particularized  guarantees of   trustworthiness."

Id.; accord  Idaho v.  Wright,  497 U.S.  805, 816-17  (1990)
                                         

(collecting cases); Manocchio, 919 F.2d at 773.  The majority
                                         

properly  holds  that  the  EXIS-derived  evidence  satisfies

neither of these criteria, but neglects to fully explain why.

          The     critical     inquiry    for     determining

"particularized  guarantees  of  trustworthiness" is  whether

"the test of cross-examination would be of marginal utility."

Wright,  110 S.  Ct. at  3149-50.32   The government  in this
                  

case,  through  Scheid,  was   permitted  to  introduce   the

statement that,  out of 14,252 bombing  and attempted bombing

incidents  in  the EXIS  database,  only  the Roslindale  and

Quincy  incidents  share the  queried  characteristics.   The

individuals who reported those bomb incidents  were witnesses

against Trenkler,  each of them testifying,  in effect: "This

bomb incident  had the  following characteristics  .  . .  ."

Despite the importance of their "testimony," neither Trenkler

nor the jury  ever saw  any of these  witnesses.   Trenkler's

attorney  was unable  to cross-examine  these witnesses  with

                    
                                

hearsay exceptions listed in Fed. R. Evid. 803(1)-(24).  

32.  The  residual  hearsay  exception contained  in  Fed. R.
Evid. 803(24), under which the EXIS evidence was admitted, is
not a  "firmly  rooted  hearsay  exception."   See  Idaho  v.
                                                                     
Wright,  497  U.S.  805,  817 (1990);  Government  of  Virgin
                                                                         
Islands v. Joseph, 964 F.2d 1380, 1387 (3d Cir. 1992). 
                             

                             -50-
                                          50


respect to  their credibility and reliability.   Because they

were  not subject  to cross-examination,  neither we  nor the

jury  will  ever  know,  for  example,  the  answers  to  the

following questions.  Were the authors of these reports  bomb

experts?   Were they even  police officers?   Did they follow

certain procedures  in compiling  evidence?  In  filing their

reports?  What criteria did they use for determining that the

device in question was  a quote "bomb"?   Did they even  have

first hand knowledge of  the devices, or was the  information

provided to them second-hand from lay  witnesses?  Scheid did

not  know the  answers to  these questions,  nor did  he have

first hand  knowledge of  the incidents themselves,  supra p.
                                                                      

34,  thus making  it  impossible for  Trenkler's attorney  to

effectively cross-examine  him.   Moreover,  Scheid  admitted

that  the bomb reports need  not be signed,  and that nothing
                                                      

required the author  of a submitted  report to have  personal

knowledge of its contents.33

          The majority  also alludes  to  a potentially  more

pernicious problem concerning the EXIS-derived evidence.  The

majority  notes that  the database  entry for  the Roslindale

incident   lists  approximately   twenty-two  characteristics

                    
                                

33.  Even  the majority  questions the  validity of  the EXIS
conclusion that only the  Roslindale and Quincy devices share
the  same  characteristics.    As the  majority  points  out,
because we  know absolutely nothing about  how the underlying
EXIS reports were generated, there is no way to know what the
absence of an item at a bomb site means.  Both Scheid and the
government's explosives expert admitted as much.  Supra n.21.
                                                                   

                             -51-
                                          51


describing  that  incident, but  Scheid,  inexplicably, chose

only  to query ten  of those characteristics.34   Supra n.21.
                                                                   

The  majority notes  that there  is nothing  to suggest  that

these  ten  characteristics are  more  important  to a  bomb-

signature analysis than any  of the other characteristics not

chosen.  Scheid offers  no reason why he chose to  query only

certain generic characteristics instead  of the more specific

characteristics of  the Roslindale bomb, which  would be more

evincing of  a "signature."   For example, the  Quincy device

would not have been a match if Scheid had queried  any of the

following  characteristics of the  Roslindale bombing: Futaba

antenna, Rockstar detonator, use of dynamite, nails, glue, 6-

volt battery,  slide switch,  paint, magazine page,  or black

electrical  tape.    The   majority  leaves  the  implication

unspoken.     I  will  not  be  so  discreet.    The  obvious

implication   is   that    Scheid   chose   the    particular

characteristics in an attempt to find a match with the Quincy

device.   This  implication  is enforced  by  the fact  that,

                    
                                

34.  The  queried   characteristics  were  1)   bombings  and
attempted bombings; 2) involving cars or trucks; 3) with bomb
placed  under the car or  truck; 4) using remote-control; and
5) magnets.  EXIS listed seven incidents which included these
characteristics.   Scheid testified that he  then performed a
manual   query   of   the   seven   incidents   using   other
characteristics of  the Roslindale  bombing.  He  checked the
other  incidents to  see if  they involved  1) duct  tape; 2)
soldering;  3) AA batteries; 4) a toggle switch; and 5) round
                                                                         
magnets.   Scheid  did  not  check all  14,252  bombings  and
attempted bombings for these latter characteristics, only the
seven.  

                             -52-
                                          52


according to Scheid's own  testimony, the Quincy incident was

not  entered into  the  database until  after the  Roslindale
                                                         

incident.   That  is,  government agents  brought the  Quincy

bombing  to  Scheid's  attention   when  they  asked  him  to

investigate the Roslindale bombing.  

          The majority  thinks these concerns go  more to the

weight  of the  evidence than  to its  admissibility;  to the

contrary,  they go directly  to the  question of  whether the

evidence  has  particularized  guarantees of  trustworthiness

under  the Confrontation  Clause.   They demonstrate  that it

does not.  Because  the reports upon which the  EXIS evidence

is  based are  inherently  and utterly  unreliable, the  EXIS

evidence  itself is  inherently and  utterly unreliable,  and

Trenkler's Sixth  Amendment right  to confront  the witnesses

against him was violated.  See  Wright, 497 U.S. at 805.  The
                                                  

question then becomes whether  this error was harmless beyond

a reasonable doubt.35

                    
                                

35.  This Circuit has demonstrated  that it is not shy  about
applying  the  harmless  error  rule to  sustain  a  criminal
conviction, but rather, shows  a persistent inclination to so
rule.   See, e.g., United  States v. Romero-Carri n,  1995 WL
                                                               
258843 (1st Cir.);  United States v. Cotal-Crespo, 47  F.3d 1
                                                             
(1st  Cir. 1995); United States  v. Smith, 46  F.3d 1223 (1st
                                                     
Cir.  1995); United States v.  Lewis, 40 F.3d  1325 (1st Cir.
                                                
1994);  United States v.  Tuesta-Toro, 29 F.3d  771 (1st Cir.
                                                 
1994); Singleton  v. United  States,  26 F.3d  233 (1st  Cir.
                                               
1994);  United States v. Isaacs, 14 F.3d 106 (1st Cir. 1994);
                                           
United  States v. Welch; 15 F.3d 1202 (1st Cir. 1993); United
                                                                         
States v. Sep lveda,  15 F.3d  1161 (1st  Cir. 1993);  United
                                                                         
States v.  Innamorati, 996 F.2d  456 (1st Cir.  1993); United
                                                                         
States  v. Williams,  985 F.2d  634  (1st Cir.  1993); United
                                                                         
States  v.  Spinosa, 982  F.2d  620 (1st  Cir.  1992); United
                                                                         

                             -53-
                                          53


                             IV.
                                         IV.
                                            

          Under  the  harmless  beyond  a   reasonable  doubt

standard, we  must vacate  the conviction  if there  is "some

reasonable possibility that error of constitutional dimension
                                  

influenced the jury in reaching [its] verdict." United States
                                                                         

v. Majaj, 947  F.2d 520,  526 n.8 (1st  Cir. 1991)  (emphasis
                    

added) (quoting United States v. Argentine, 814 F.2d 783, 789
                                                      

(1st Cir. 1987)).  See also United States v. Flores, 968 F.2d
                                                               

1366, 1372 (1st  Cir. 1992).   Under this  standard, we  will

only  find  harmless  error  when  the  untainted   evidence,

standing  alone,  provides  "overwhelming  evidence"  of  the

defendant's guilt.  Clark v. Moran, 942 F.2d 24, 27 (1st Cir.
                                              

1991).   In  conducting this inquiry,  we "must  consider the

evidence  as a  whole,  weighing the  effect  of the  tainted

evidence  against  the  effect  of that  evidence  which  was

properly admitted."   Id. (citing Lacy  v. Gardino, 791  F.2d
                                                              

980, 986  (1st  Cir.), cert.  denied, 479  U.S. 888  (1986)).
                                                

Thus, the  relative strength of the tainted evidence -- i.e.,

                    
                                

States v.  Figueroa, 976 F.2d  1446 (1st  Cir. 1992);  United
                                                                         
States v. Tejeda, 974 F.2d 210 (1st Cir. 1992); United States
                                                                         
v.  Parent, 954  F.2d 23  (1st Cir.  1992); United  States v.
                                                                      
Karas, 950 F.2d 31 (1st Cir. 1991); United States v. Minnick,
                                                                        
949 F.2d 8 (1st Cir. 1991); United States v. Maraj, 947  F.2d
                                                              
520 (1st  Cir. 1991); Clark v.  Moran, 942 F.2d  24 (1st Cir.
                                                 
1991); United States v. McMahon, 938 F.2d 1501 (1991); United
                                                                         
States v. Brown, 938 F.2d 1482 (1st Cir. 1991); United States
                                                                         
v.  Ellis, 935  F.2d 385  (1st cir.  1991); United  States v.
                                                                      
Sutherland, 929  F.2d 765 (1st  Cir. 1991); United  States v.
                                                                      
Wood, 924 F.2d 399  (1st Cir. 1991); United States  v. Paiva,
                                                                        
892 F.2d 148 (1st Cir. 1989). 

                             -54-
                                          54


its potential effect on  the jury -- is a  highly significant

consideration.

          As I  see it, there  are three related  reasons why

admission of the EXIS  evidence cannot be considered harmless

beyond a reasonable doubt.  First, it is clear to me that the

district court  relied on the  improper EXIS evidence  in its

decision  to allow the government  to present evidence of the

Quincy incident  to  the jury  to prove  identity under  Rule

404(b).

          At the hearing  on its  motion in  limine to  admit

evidence of the  Quincy incident under Fed. R.  Evid. 404(b),

the government presented the  testimony of Scheid,  regarding

the  EXIS  computer  analysis,   and  the  testimony  of  the

government's bomb expert, Waskom,  who testified that, in his

opinion, the  Quincy and  Roslindale devices were  so similar

that they must have been built by the same person.   In turn,

Trenkler presented expert testimony that the devices were too

different for anyone  to be  able to determine  if they  were

built by the same  person.  After hearing this  evidence, the

district court concluded that  "the similarities [between the

two incidents] are sufficient to admit the evidence under the

rules established . . . by the First Circuit."

          The majority states that,  based upon its review of

the record, it is convinced that the EXIS-based evidence "was

not a  critical factor  in the  district court's decision  to

                             -55-
                                          55


admit the Quincy bomb evidence for purposes of identity.  The

EXIS-derived  evidence  was merely  cumulative, corroborating

the testimony of the  government's explosives expert."  Supra
                                                                         

pp.  39-40.   Yet the record  demonstrates that  the district

court  judge  thought otherwise  when  she  decided to  admit

evidence of the 1986 Quincy incident.  In her oral opinion on

the government's  motion, the  district court judge  began by

summarizing the testimony of Waskom, and then stated: "Adding
                                                                         

to  this evidence,  the  statistical evidence  from the  EXIS
                             

system, I am persuaded that the  two devices are sufficiently

similar  to prove that the  same person built  them, and thus

relevant to the issues in this case."  (emphasis added).  The

district  court  judge did  not  say that  the  EXIS evidence

"corroborated" Waskom's testimony.  She stated that, when she

adds  the EXIS  evidence to  Waskom's testimony,  she becomes
                

convinced that the  two devices are sufficiently similar.  It

is plain that  the district  court judge relied  on the  EXIS

evidence to  form the  critical final  link  between the  two

devices.  Indeed, in arguing its motion, the government chose

to  first present the EXIS  evidence and then  to present the

Waskom testimony,  suggesting that it intended  the latter to

corroborate  the  former.    The district  court's  erroneous

determination that  the EXIS evidence was  admissible led not

only to  the jury hearing that evidence, but also to the jury

hearing Waskom's testimony with respect to the two incidents.

                             -56-
                                          56


I cannot  agree, therefore,  that admission of  this evidence

was harmless beyond a reasonable doubt.

          The  second  reason  that  admission  of  the  EXIS

evidence cannot  be considered harmless is that  this type of

"scientific" evidence  is too  misleading, too powerful,  and

has  too  great  a potential  impact  on  lay  jurors, to  be

disregarded as harmless.

          The  EXIS-derived  evidence was,  in the  best case

scenario, unintentionally misleading, and, in the  worst case

scenario,  deliberately skewed.    Scheid testified  that, in

entering information about the  Quincy incident into the EXIS

database, he relied solely on a laboratory report prepared in

1986 by  investigators from  the Massachusetts  Department of

Public  Safety.  This report  does not state  that the Quincy

device was  attached to the  underside of the  Capeway truck.

Rather,  it  refers  only   to  an  "[e]xplosion  on  truck."

Somebody must have given Scheid further information about the

Quincy  explosion because  he  entered "under  vehicle" as  a

characteristic  of  the  Quincy   incident.    The   majority

acknowledges these facts but, inexplicably, makes no comment.

See  supra n.8.  These facts are important for three reasons.
                      

First,  they  illustrate the  fallibility  of  the underlying

reports.   How many of  the other 14,232  reports had similar

defects?   Second, they illustrate  how easily  one wrong  or

incomplete  entry can affect a  query result.   If Scheid had

                             -57-
                                          57


actually followed  the report, the Quincy  incident would not

have  matched the Roslindale  bombing because  Scheid's query

entry  was  for  a  bomb "under  vehicle."36  Finally,  these

facts  indicate  that  the  EXIS  test  was  skewed  (whether

intentionally or unintentionally) to find a match between the

Quincy and Roslindale incidents.37

          The  EXIS-derived  evidence   is  also   misleading

because it focuses the jury's attention on  the trees instead

of the forest. By  focusing on similar minor aspects  between

the  two devices -- e.g., duct tape, magnets and soldering --

the  majority  completely brushes  aside  the  fact that  the

central and most  important ingredient in the  two devices is

fundamentally different.   The central ingredient  in a bomb,

one would think, is  the explosive content (in much  the same

way that the central ingredient in a high-performance  car is

the engine).  The Roslindale bomb used two to three sticks of

dynamite  -- a very  powerful explosive.   The  Quincy device
                    

used an M-21 Hoffman  artillery simulator, which is a  device

                    
                                

36.  The majority acknowledges that "[t]he statement that out
of more  than 14,000 bombing and  attempted bombing incidents
in the EXIS database only the Roslindale and Quincy incidents
share  the eight  specific queried  characteristics (bombings
and attempted bombings, attached  under car or truck, remote-
control,  round magnets,  duct  tape,  solder, AA  batteries,
toggle switches) is a  fairly powerful statement, but perhaps
                                                                         
a somewhat misleading one."  Supra n.21 (emphasis added).
                                              

37.  As discussed previously, there is other  evidence (i.e.,
the suspect nature of Scheid's query choices) which  tends to
show  that the  EXIS query  may have been  skewed to  reach a
predictable result.  See supra pp. 50-51. 
                                          

                             -58-
                                          58


used  by the  military to  simulate, in  a safe  fashion, the
                                                                    

flash and noise of artillery.  The simulator is, in effect, a

firecracker-like device; it has no where near the strength of

dynamite.   In stark contrast to dynamite, a simulator is not

designed to cause physical or property damage.  Indeed, while

the Roslindale  device created  an explosion large  enough to

kill, the Quincy device caused no visible damage to the truck

it  was placed  under.   Equating  the  two devices  is  like

equating a BB gun with a high caliber rifle.38

          The misleading nature of the EXIS-derived statement

is compounded  by the nature  of its  source, and the  way in

which it  was presented  to the  jury.  Not  only is  it rank

hearsay evidence, it is hearsay evidence wrapped in a  shroud

of "scientific" authenticity.  This  is not a paid government

expert testifying that, in his opinion, the two  devices were
                                                  

built by the same  person; this is a computer  declaring that
                                                         

the two devices  were built  by the same  person.   Computers

deal in facts,39  not opinions.   Computers are  not paid  by

                    
                                

38.  Federal authorities apparently  did not deem the  Quincy
incident serious enough to  warrant bringing charges  against
Trenkler  pursuant   to   18  U.S.C.      844(i)   (malicious
destruction of property by means of an explosive), one of the
statutes  at issue in this case.  State charges stemming from
the Quincy incident were dismissed.

39.  Of course,  the facts generated by the computer are only
as accurate  and reliable  as the  facts fed  into it  by its
operator.  As the majority recognizes, in this case the facts
fed  into  the  computer   were,  unbeknownst  to  the  jury,
manifestly unreliable.   Thus, its conclusion  based on those
facts is similarly unreliable.

                             -59-
                                          59


one side to testify.  Computers do not have  prejudices.  And

computers  are not subject  to cross-examination.   Moreover,

the  chart of the EXIS  queries performed by  Scheid, and the

printouts of  the results  of those queries,  were introduced

into  evidence  and  presented   as  exhibits  to  the  jury.

Consequently, the jury had this misleading, physical evidence

with them in the  jury room during deliberations.40   Does it

not  stand to reason that  the lay juror  will accord greater

weight to a computer's written findings than to the testimony

of a government expert witness?   The common-sense answer is,

of course.41

                    
                                

40.  Common sense  tells us that  lay jurors often  will lend
more weight to tangible evidence than to oral testimony.  See
                                                                         
generally  22  C.  Wright  &  Graham,  Federal  Practice  and
                                                                         
Procedure,    5173 (1978)  ("It is  often  asserted that  the
                     
psychological  impact  of  the  concrete has  a  capacity  to
suggest  matters  not  proved,  to  lead  the  jury  to  draw
unconscious inferences that would not be drawn if  the object
was  the subject of  testimony rather than  being produced in
court.") (internal  citations omitted).   See also  People v.
                                                                      
Moore, 525 N.E.2d 460, 463 (N.Y. 1988) (Kaye, J., dissenting)
                 
("No  point in  a  trial  can  be  more  critical  than  jury
deliberations.   Materials taken into the jury  room at those
crucial moments may well influence the verdict.").

41.  As one commentator has noted:

               Scientific  evidence  impresses
               lay  jurors.    They   tend  to
               assume it is more  accurate and
               objective  than lay  testimony.
               A    juror   who    thinks   of
               scientific  evidence visualizes
               instruments      capable     of
               amazingly  precise measurement,
               of   findings  arrived   at  by
               dispassionate scientific tests.
               In  short, in  the mind  of the

                             -60-
                                          60


          The majority decision in  this case not only defies

common sense,  it is also contrary  to our precedent.   In De
                                                                         

Jes s-R os, 990  F.2d 672, we  held that the  defendant's due
                      

process rights were violated when the district court admitted

certain    identification    testimony    by    a    witness.

Significantly, we  concluded that the error  was not harmless

beyond  a  reasonable  doubt,  even  though  another  witness

testified at trial that he also had identified the defendant.

Rather than concluding, as  the majority does here, that  the

one   erroneously   admitted   identification   was   "merely

cumulative" of the other, the court reasoned:

          [T]here is  no way for us  to discern the
          role that  Rivera's identification played
          in  the jury's  deliberations.    We  are
          concerned  that the  jury  may have  been
                                                               
          persuaded to  convict  by the  very  fact
                                                               
          that   there   were  two   witnesses  who
                                                          
          identified [the  defendant].  It  is also
          possible that the jury relied solely upon
          the testimony of  Rivera in reaching  its

                    
                                

               typical lay juror, a scientific
               witness has a  special aura  of
               credibility.

Imwinkelried, Evidence Law and  Tactics for the Proponents of
                                                                         
Scientific Evidence, In Scientific and Expert Evidence 33, 37
                                                                  
(E.  Imwinkelried  ed.  1981).     See  also  Giannelli,  The
                                                                         
Admissibility of  Novel Scientific  evidence: Frye  v. United
                                                         
States, a  Half-Century Later, 80  Colum. L. Rev.  1197, 1237
                                         
(1980)  ("The  major danger  of  scientific  evidence is  its
potential  to  mislead  the   jury;  an  aura  of  scientific
infallibility may  shroud the evidence and thus lead the jury
to accept  it without  critical scrutiny.");  22 C.  Wright &
Graham, supra note 41,   5217 ("Scientific . . . evidence has
                         
great  potential for misleading the jury.   The low probative
worth can often be concealed in the jargon of some expert . .
.").

                             -61-
                                          61


          conclusion.    Thus,  we find  reasonable
          doubt exists as to whether the jury would
          have  convicted   [the  defendant]  based
          solely   upon   Mejias's   identification
          testimony.

Id. at 678  (emphasis added).   Is it  not equally  plausible
              

that  the jury  in  this case  "may  have been  persuaded  to

convict"  by the very fact that two "witnesses" -- Waskom and

the  EXIS-derived evidence  --  identified the builder of the

Quincy  device as the builder of the  Roslindale bomb?  Is it

not also equally plausible  that the jury relied solely  upon
                                                                   

the  EXIS-derived  evidence   in  reaching  its   conclusion?

Because the EXIS-derived statement  came from a computer, and

was presented in tangible, exhibit  form, it is more powerful

and  seemingly credible  evidence  to  a  lay jury  than  the

testimony of a human being.  The jury may well have relied on

the  EXIS-derived  evidence  to  break the  tie  between  the

competing experts.   This  is particularly  so since, as  the

trial   judge   noted,   defendant's   expert   witness   had

"considerably  more  experience in  making  .  . .  signature

comparisons."   Since  the EXIS-derived  evidence  could well

have   been  "the  clincher"  for  the  jury,  it  cannot  be

considered harmless  beyond a reasonable doubt.   See Coppola
                                                                         

v. Powell, 878 F.2d 1562 (1st Cir. 1989).
                     

          The  third  reason  that  admission  of   the  EXIS

evidence is  not harmless beyond  a reasonable doubt  is that

the other evidence  against Trenkler was  not "overwhelming."

                             -62-
                                          62


See Clark,  942  F.2d  at  27.   The  majority  points  to  a
                     

conglomeration   of  other  testimony   in  support   of  its

conclusion   that  there   was   "substantial  evidence"   of

Trenkler's guilt,  independent of  the Quincy incident.   The

test,  of  course,  is  not  whether  there  is  "substantial

evidence"   of  Trenkler's   guilt  but   whether  there   is

"overwhelming  evidence"  of  Trenkler's   guilt.    The  two
                         

standards are qualitatively and quantitatively different.  In

any case, I will  begin by addressing Trenkler's "statements"

to government agents.

          ATF  Agent  D'Ambrosio  testified  that   he  asked

Trenkler  to  draw  a  sketch of  the  Quincy  device,  which

Trenkler  did.    D'Ambrosio  then  told  Trenkler  that  the

Roslindale bomb  also used  remote control, but  that, rather

than a firecracker type device, it used dynamite.  D'Ambrosio

asked  Trenkler  how, in  light  of these  facts,  the wiring

diagram  he had just drawn  for the Quincy  device would have

been  different for the Roslindale bomb. D'Ambrosio testified

that Trenkler then drew  a diagram which showed  two blasting

caps  inserted into  two sticks  of  dynamite.   The majority

considers  this  significant  evidence  of  Trenkler's  guilt

because the fact that the Roslindale bomb used blasting  caps

had not been publicly disclosed.  The majority fails to note,

however, that D'Ambrosio actually testified that at least two
                                                                     

blasting caps  were used  in the  Roslindale bombing.   Thus,

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Trenkler's drawing of only two blasting caps was not an exact

match.  Moreover,  the jury heard evidence that  Trenkler had

extensive knowledge of both electronics and explosives, so it

is  not necessarily  significant  that Trenkler  was able  to

reconstruct an  aspect of  the Roslindale bomb,  particularly

considering the  information concerning the bomb  provided to

Trenkler  by D'Ambrosio.    Trenkler  merely identified  that

blasting caps  were a likely way in which a bomb of this size

and  power would  be  constructed.   In  the absence  of  any

testimony  that the use of blasting caps is unusual or unique

(a proposition which is highly unlikely), the jury could only

speculate as to the significance of the drawing.

          The majority  also finds significance in  ATF Agent

Leahy's testimony that Trenkler  said to him: "If we  did it,

then only we know about it . . . how will you ever find out .

.  . if neither one of us  talk[]?"  The majority paints this

statement in a confessional light.  This testimony may or may

not have  been of some  circumstantial relevance to  the jury

(although  standing  alone,  of   course,  it  would  not  be

sufficient  to sustain a conviction).  But, upon review, when

the court  is looking  for "overwhelming evidence  of guilt,"

one would  think the court would  not have to resort  to this

sort of  an ambiguous, taunting statement.42   Similarly, the

                    
                                

42.  In  Coppola,  for  example,  we lent  little  weight  to
                            
defendant's statement to  another inmate -- "What did  I have
to  lose?"  --  in response  to  a  question  whether he  had

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court notes that  there was evidence  that Trenkler and  Shay

knew  each other,  and that  Trenkler  had knowledge  of both

electronics and  explosives.   While the jury  might consider

this type of circumstantial  evidence relevant, it can hardly

be  said  that  it   does  much  in  the  way   of  providing

"overwhelming  evidence" of  defendant's guilt.   Cf.  United
                                                                         

States  v.  Innamorati, 996  F.2d  456, 476  (1st  Cir. 1993)
                                  

(holding that the  erroneous admission  of inculpatory  grand

jury testimony  was harmless  beyond a reasonable  doubt when

seven people testified at trial that defendant was engaged in
                 

marijuana and cocaine dealing, and drugs and money were found

in defendant's constructive possession).

          The majority  relies most heavily on  the testimony

of David  Lindholm, who testified that  Trenkler confessed to

building the Roslindale bomb.  But Lindholm had  some serious

credibility problems which make his testimony "shaky," to say

the  least.  Lindholm  testified that  he met  Trenkler while

Lindholm was  serving a  97-month sentence for  conspiracy to

distribute marijuana  and tax evasion.   He further testified

that he was in the marijuana business from approximately 1969

through 1988, and that he did not pay any income taxes during

that  time.  Lindholm also testified that, in order to secure

bank loans to purchase property during that period, he showed

several  banks false  income tax  returns.   On the  basis of

                    
                                

committed the rape.  See 878 F.2d at 1569-70.  
                                    

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Lindholm's shady  past alone, the jury  might have completely

disregarded his testimony.

          But Lindholm also had some less obvious credibility

problems.   The circumstances of his  meeting Trenkler strike

me as a little too coincidental.  On December 17, 1992, after

a year and a half incarceration in Texas, Lindholm is brought

back to Boston concerning certain unspecified charges related

to his conviction.  He is then placed in the orientation unit

at  the Plymouth  House of  Correction where he  meets Alfred

Trenkler, who is being held in connection with the Roslindale

bombing.   The two  subsequently discover that  they have  an

extraordinary amount  in common.   First, they are  both from

the town of Milton, Massachusetts.  Second, Trenkler attended

Thayer Academy and Milton Academy, and Lindholm's father also

attended Thayer Academy and Milton Academy.  Third, they both

lived for a time -- overlapping by one year --  on White Lawn

Avenue  in  Milton.     Based  on  these  commonalities,  and

Lindholm's   generosity  in  sharing  his  knowledge  of  the

criminal   justice  system   with  Trenkler,   they   form  a

friendship.  Trenkler then,  allegedly, confesses to Lindholm

that he built the bomb.

          In  my  view,  a  reasonable juror  might  question

whether Lindholm  was placed in  the orientation unit  by the

government  for the  purpose of  obtaining a  confession from

Trenkler.    If so,  that  juror  would  likely  wonder  what

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Lindholm got in return.  Not surprisingly, Lindholm testified

that he had no agreements with the government and that he did

not   receive   any   promises   or   inducements   for   his

testimony.43  He  did testify on  cross-examination, however,

that he knew, when he provided the information about Trenkler

to the  government, that the  only way his  97-month sentence

could  be reduced was if  he supplied new  information to the

government.44

          We  do  not  know how  much  weight  the  jury gave

Lindholm's  testimony, but we do know that, at least on paper

-- for we  did not observe his demeanor at  trial -- Lindholm

                    
                                

43.  If  the  government  makes  an  explicit  promise  to  a
witness,  of course, this will  come out at  trial and likely
decrease the  witness's credibility in the eyes  of the jury.
But if the government lawyers explain to the witness why they
do  not  want to  make  any  explicit promises,  leaving  the
inference that one good deed begets  another, the witness can
testify that he  has no agreement.   I note, in this  regard,
that  this court  has previously  questioned the  validity of
these "no agreement" statements by criminal defendants.  See,
                                                                        
e.g., Coppola, 878 F.2d at 1569-70.
                         

44.  When  asked  on  direct  examination  why  he testified,
Lindholm stated:

          Since  I have  been incarcerated,  I have
          come to realize that the sole function of
          prison  is not just  punishment.  I think
          rehabilitation   is   important  for   an
          individual.   And  I  think, when  I talk
          about     rehabilitation,      I     mean
          rehabilitation  of  a person's  values in
          terms of how they live one's life and the
          decisions   they    make,   knowing   the
          difference   between  what's   wrong  and
          what's right, what's illegal and legal.

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had some significant  credibility problems.  Consequently,  I

cannot conclude beyond a reasonable doubt that the jury would

have believed his  testimony; particularly in a  case such as

this  where there  is absolutely  no physical  evidence tying
                                                                   

Trenkler  to  the bombing.   Cf.  Coppola,  878 F.2d  at 1571
                                                     

(discounting  inculpatory  testimony  of three  jail  inmates

because  it "raises  serious  questions  of credibility"  and

noting the absence of  any conclusive physical evidence tying

the defendant to the  crime).  The only evidence  coming near

thatlevelofreliability wastheimproperlyadmitted EXISevidence.

          Absent the EXIS-derived evidence,  the government's

case   against  Trenkler   consists  of   a   smorgasbord  of

inconclusive  circumstantial  evidence   and  an   inherently

unreliable  alleged jailhouse  confession.   Faced with  this

sort  of evidence, a reasonable jury  would probably look for

some  sort of tangible evidence  upon which to  hang its hat.

The  EXIS-derived evidence was just that.  Because it was the

only ostensibly  conclusive evidence  tying  Trenkler to  the

crime,  it may  have been  the clincher  for the  jury.   See
                                                                         

Coppola, 878 F.2d  at 1571.   It was  therefore not  harmless
                   

beyond a reasonable doubt.

                              V.
                                          V.
                                            

          A horrible crime was  committed in which one police

officer was  killed and  another seriously injured.   Society

rightfully demands that the guilty be apprehended, tried, and

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punished.  But the distinguishing feature of our legal system

is  that  even  those   charged  with  grotesque  crimes  are

guaranteed certain  constitutional rights intended  to ensure

that  they receive a fair trial.  Unfortunately, and with all

due respect to  my brethren, I believe  the defendant's right

to  a  fair  trial  was  violated  when  the  government  was

permitted   to  introduce  the  highly  prejudicial  evidence

derived from the EXIS computer database.   Because this error

so severely  violated  defendant's Sixth  Amendment right  to

confront the witnesses against him, and because the remainder

of  the  evidence  against  him  was  not  "overwhelming,"  I

dissent.

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