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

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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.

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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.

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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

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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

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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.

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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,

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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

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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.

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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.

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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

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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.

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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

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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.

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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.

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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

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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

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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,

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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.

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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

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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.

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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

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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.

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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.

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44

Dissent follows.
Dissent follows.

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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.

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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."

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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)).

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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

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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).

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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.

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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.

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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

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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).

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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

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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.

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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

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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.

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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.

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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

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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 . .
.").

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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."

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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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