Filed 12/29/22 P. v. Perez CA1/4
NOT TO BE PUBLISHED IN OFFICIAL REPORTS
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IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA
FIRST APPELLATE DISTRICT
DIVISION FOUR
THE PEOPLE,
Plaintiff and Respondent,
A165848
v.
JAIME BRISENO PEREZ, (Kern County
Super. Ct. No. BF176180A)
Defendant and
Appellant.
Defendant appeals his conviction for first-degree murder
after a jury trial in which the court admitted testimony from a
criminalist who relied in part upon DNA evidence generated with
the use of the TrueAllele probabilistic software program
(TrueAllele). Defendant sought to discover TrueAllele’s source
code, and he argues that the trial court’s failure to order
disclosure thereof violated his right to confrontation under the
Sixth Amendment of the United States Constitution. We affirm.
BACKGROUND
The People charged defendant with the first degree murder
of Kyle Ramirez, further alleging that defendant used a knife to
commit the crime and had one prison prior (Pen. Code, §§ 187,
subd. (a), 667.5, subd. (b), 12022, subd. (b)(l)).
1
At trial, defendant’s brother, Ricardo Briseno, testified
that, in the late afternoon on April 14, 2018, Ricardo drove his
younger brother to their parents’ house to pick up clothing.
Ricardo went into a bedroom in the garage to see if defendant
was home. Ricardo saw a body on the floor covered in bags and a
blanket, and defendant asleep on the bed with what appeared to
be a gun. Ricardo left quickly with his younger brother and
called 911.
Deputy Paxson was dispatched to the house at issue around
5:15 p.m. He had been told defendant had a gun, so he remained
outside and waited for backup. When more deputies arrived,
Paxson used another deputy’s PA system to call for defendant to
leave the house, but there was no response. Police entered the
house, but did not find defendant. After a second search of the
house about fifteen minutes later, police located defendant in a
closet and took him into custody. Photos of defendant taken at
the time showed redness on his chest and knuckles, minor
scratches on his arms, a scratch on his torso, and two injuries to
his ears. Paxson agreed on cross-examination that defendant had
minor scratches. Police found a knife in defendant’s pocket.
Defendant told Paxson that his name was Esteban, but Paxson
knew Esteban, one of defendant’s brothers, from a prior contact.
Deputy Sanchez helped process the crime scene. The
victim’s body was on the floor in the bedroom, wrapped in a
blanket with a trash bag and towel over his head. There was a
leather belt around the victim’s midsection, along with a long,
black curly hair on the victim’s elbow. The victim had a large
2
laceration on the back of his head, two large cuts to his throat,
somewhat superficial stab wounds to his chest, and his legs were
bound with a dog leash. An air soft gun was near the bed. A
bottle of bleach and plastic trash bags were on the floor. Police
seized a pair of blue and white Nikes near the bed, a trash bag
from the bedroom containing jeans and a red t-shirt, and a trash
bag from the laundry room containing a pair of grey and white
Nikes. Photos were taken of bloody shoe prints on the floor, and
there appeared to be blood spatter on the red t-shirt. A first aid
kit containing items indicative of drug sales was found in the
bedroom, along with baggies containing what appeared to be
marijuana. Police observed a drawing on the bedroom wall, and
the word “Trigger” appeared therein.
Detective Daniel Perez collected buccal swabs from
defendant and Esteban for DNA testing. He testified that, four
weeks before trial, Esteban had also been arrested for the
victim’s murder after police learned that his alibi was false.
Defendant’s father testified that defendant sometimes
stayed in the bedroom garage at his house because defendant did
not have his own home. On April 13, 2018, defendant’s father
saw defendant with another person returning to the house with
beer. Defendant’s father did not recognize the man, but he
described him as Hispanic and about defendant’s age.
Kyle Ramirez’s sister testified that she texted with her
brother around 12:22 p.m. on April 13, 2018, and her brother said
3
he was at Trigger’s pad.1 She testified on cross-examination that,
after the text, she spoke to her brother on the phone, asked who
“Trigger” was, and he replied, “Jaime.” She testified that she had
previously given her brother rides to Trigger’s house and knew
the location, and her brother told her that he had been friends
with defendant since age 12 or 13.
Forensic pathologist Dr. Whitmore performed Ramirez’s
autopsy. He testified there was a canvas belt around Ramirez’s
neck, and the buckle had cut into Ramirez’s skin; a belt around
Ramirez’s midsection had restrained his upper extremities, and a
leash had been wrapped around his ankles. There were signs of
strangulation and cuts made with a sharp instrument on the
body. An injury to the back of Ramirez’s head going down to the
skull bone appeared to have been caused by something heavy and
linear. There were bruises on the back of the victim’s hands, a
rib facture on his left side, a fracture to his jawbone, and a knife
wound to his chest that was not very deep. The base of Ramirez’s
skull was fractured, and there was blood in his brain. Brain
swelling indicated that head trauma was inflicted while Ramirez
was alive. Dr. Whitmore opined that the cause of death was
strangulation, but the head injuries also contributed, and the
manner of death was homicide. He could not estimate the time of
death or say which particular knife caused Ramirez’s stab
wounds.
1 The trial court admitted this evidence for a limited
purpose and instructed the jury that it may consider this
evidence only as circumstantial evidence that Ramirez was alive
at the time.
4
Sarah Kidwell, a criminalist for the DNA analysis unit of
the Kern County Regional Crime Lab, performed the DNA
interpretation in this case. Reference DNA samples were taken
from the victim, defendant, Esteban, and Esteban’s wife. DNA
testing showed that the hair from the victim’s elbow, which was
the only hair retrieved with a root suitable for DNA testing,
belonged to defendant.
Blood stains from the exterior of the blue and white Nike
shoes and the grey and white Nike shoes, the red t-shirt, and the
pair of jeans found at the crime scene were swabbed for DNA and
tested. The victim was a match for each blood stain.
The interior neck area of the red t-shirt was swabbed for
DNA, as was the interior waistband of the jeans, the interiors of
the grey and white and blue and white Nike shoes, the knife
found on defendant, the belt around the victim’s neck, the belt
around the victim’s midsection, and the leash around the victim’s
ankles.
The DNA profile from the interior of the red t-shirt was a
mixture. Neither the victim nor defendant could be excluded as a
potential contributor. The victim was 1.8 quintillion times more
likely to be a match than a random Hispanic person, defendant
was 4.9 billion times more likely to be a match than a random
Hispanic person, and no conclusion could be drawn for Esteban.
There were four contributors for the DNA profile from the
interior waistband of the jeans, and three of the four known
reference samples could not be excluded. The victim was 46
trillion times more likely to be a match than a random Hispanic
5
person, defendant was 99 trillion times more likely to be a match
than a random Hispanic person, and Esteban was 1.1 million
times more likely to be a match than a random Hispanic person.
The DNA profile obtained from the blade of the knife was a
mixture, and neither defendant nor Esteban could be excluded. A
match between the DNA from this item and defendant was 2.5
billion times more likely than a coincidental match to a random
Hispanic person, and a match between this item and Esteban
was 16 million times more likely than a coincidental match to a
random Hispanic person. Kidwell confirmed that defendant’s
statistical numbers were higher. With respect to the DNA from
the knife handle, neither defendant nor Esteban could be
excluded. A match for defendant was 3.7 billion times more
likely than a coincidental match to a random Hispanic male. A
match between Esteban and the DNA obtained from the knife
handle was 41 million times more likely than a coincidental
match to a random Hispanic male.
The DNA profile obtained from the belt around the victim’s
midsection was a mixture. The victim was 4.3 septillion times
more likely to be a match than a random Hispanic male. None of
the other known reference samples could be excluded.
The DNA profile obtained from the leash around the
victim’s ankles was a mixture. A match for the victim was 220
billion times more likely than a coincidental match to random
Hispanic male. A match for defendant was 1.5 billion times more
likely than a coincidental match to random Hispanic male. And a
6
match for Esteban was 190,000 times more likely than a
coincidental match to random Hispanic male.
Traditional STR testing and manual DNA interpretation
was performed on the DNA obtained from the belt around the
victim’s neck, and this DNA matched that of the victim.
The DNA profile from the interior of the grey and white
Nike shoes was a mixture. The victim was the major contributor,
and a match to the victim was 740 septillion times more likely
than a random Hispanic person. With respect to the DNA profile
from the interior of the blue and white Nike shoes, neither
defendant nor Esteban could be excluded. A match for defendant
was 15 billion times more likely than a match for a random
Hispanic person, and a match for Esteban was 3.9 million times
more likely than a match for a random Hispanic person.
Where the statistical results of the DNA analysis were
higher for defendant than for Esteban, Kidwell opined the results
meant that “at least all or a portion of the profile obtained from
the evidence was more consistent with” the known reference
sample for defendant—in other words, there were “more
locations, more alleles matching [defendant] than match[ing]
Esteban.” On cross-examination, Kidwell acknowledged and
explained the concept of transfer DNA whereby humans transfer
their DNA to other objects or humans upon contact, but she
opined that it was unlikely this concept would affect major versus
minor contributor findings.
The jury returned a guilty verdict on the first degree
murder charge and found the knife use allegation true. In a
7
bifurcated proceeding, the trial court found the prison prior
allegation not true. The court sentenced defendant to a term of
25 years to life on the murder conviction, plus one additional year
for the weapon use enhancement.
DISCUSSION
We first take a moment to clarify defendant’s Sixth
Amendment claims. In his opening brief, defendant relies
primarily on Crawford v. Washington (2004) 541 U.S. 36
(Crawford), and the ensuing line of United States Supreme Court
jurisprudence precluding the admission of testimonial hearsay
against a defendant at trial (discussed, post). Defendant argues
that the trial court committed Crawford error by failing to
require disclosure of TrueAllele’s source code because: (1) the
source code is akin to a human witness and is a declarant; or
(2) the source code is itself testimonial hearsay. Thereafter,
defendant claims that he had a Sixth Amendment right to
discover the source code at the pretrial stage, referencing Davis v.
Alaska (1974) 415 U.S. 308, 320–321 (Davis), which held that the
denial of the opportunity to cross-examine a crucial adverse
witness for bias at trial violated the confrontation clause. Then,
in his reply brief, defendant appears to clarify that his argument
in this appeal is that his rights under Crawford were violated by
the trial court’s failure to order disclosure of TrueAllele’s source
code because the source code constitutes a testimonial hearsay
statement (made by TrueAllele’s programmer) that Kidwell
disclosed in her testimony. Given the lack of clarity and
8
inconsistencies in defendant’s briefing, we will address the
arguments he makes under both Crawford and Davis.
I. Additional Procedural Background
Defendant filed a pretrial discovery motion pursuant to
Penal Code section 1054 et seq. requesting the source code for
TrueAllele2. The prosecutor opposed the request, arguing that
the source code was a trade secret, and the court denied the
motion.
Subsequently, defendant filed a motion in limine, again
requesting the disclosure of all source code for TrueAllele to allow
his defense expert to testify about the potential flaws and biases
in the program and “meaningfully confront the human choices
behind the algorithm.” This motion repeated almost word-for-
word defendant’s pretrial discovery motion. The trial court heard
argument, stated that it had reviewed the law on this issue, and
denied the motion.
2 In his briefing on appeal, defendant states that TrueAllele
is a probabilistic genotyping software. Citing a law review article
(Eidelman, The First Amendment Case for Public Access to Secret
Algorithms Used in Criminal Trials, Vol. 34:4 Georgia State
Univ. L.Rev. (2018) 915, 920–921), he explains that
“[p]robabilistic genotyping differs from traditional DNA analysis
by making a sketch of a known genetic profile using the
algorithm’s input before searching for a match. . . . The output of
a program like TrueAllele is expressed as a likelihood ratio,
which is ‘a statistic that is computed by dividing (1) the estimated
probability that the owner of the DNA in the tested sample has
the suspect’s DNA by (2) the probability that a random person of
a particular race or ethnicity has the suspect’s DNA profile.’ ”
9
During trial, Kidwell testified about the DNA analysis of
physical evidence collected during law enforcement’s
investigation of Ramirez’s murder. Kidwell described the
TrueAllele software as “a way to analyze the sample essentially
to determine what genotypes are present and the probabilities of
those genotypes.” She testified that if a DNA sample is below the
threshold required to perform manual analysis for STR testing,
then TrueAllele could possibly be utilized. Kidwell described
TrueAllele as a computer software program with source code.
During Kidwell’s testimony, defendant made an oral
motion outside the presence of the jury and requested that the
court admonish the jury that he had been denied access to
TrueAllele’s source code. In response to the trial court’s
questioning during that motion, Kidwell confirmed that a
simplistic description of how she utilized TrueAllele was that she
entered data into the program, the computer asked her questions,
and she answered the questions. Kidwell elaborated that a
person, while being monitored to protect TrueAllele’s intellectual
property, could view the source code at the company’s
headquarters. She explained that she had never seen
TrueAllele’s source code, and she performed her DNA analysis
without knowing anything about the source code. During the
colloquy between court and counsel, defense counsel noted that
he had cross-examined the author of the TrueAllele source code,
Dr. Perlin, in a prior case.
10
II. The Crawford Error Claim
The Sixth Amendment’s confrontation clause provides that,
“[i]n all criminal prosecutions, the accused shall enjoy the
right . . . to be confronted with the witnesses against him.” (U.S.
Const., 6th Amend.) Crawford held that the confrontation clause
bars the admission of a testimonial hearsay statement against a
defendant at trial unless the maker of the statement is
unavailable at trial and the defendant had a prior opportunity to
cross-examine that person or the declarant appears for cross-
examination at trial. (Crawford, supra, 541 U.S. at pp. 53, 59 &
fn. 9.) The testimonial statement at issue in Crawford was made
by defendant’s wife during police interrogation, but the high
court did not precisely define the scope of statements that are to
be considered “testimonial” under the confrontation clause.
(Crawford, at pp. 38, 51, 68.) The high court did, however, cite
language in prior decisions describing testimonial statements as
including “ ‘extrajudicial statements . . . contained in formalized
testimonial materials, such as affidavits, depositions, prior
testimony, or confessions.’ ” (Id. at p. 51.)
Subsequently, the United States Supreme Court applied
Crawford to reports involving scientific test results in Melendez–
Diaz v. Massachusetts (2009) 557 U.S. 305 (Melendez–Diaz),
Bullcoming v. New Mexico (2011) 564 U.S. 647 (Bullcoming), and
Williams v. Illinois (2012) 567 U.S. 50 (Williams).
In Melendez–Diaz, which involved charges of cocaine
distribution and trafficking, crime lab analysts prepared
documents certifying that a sample of material recovered from
11
the defendant was tested and contained an illegal drug. The
certificates were sworn to before a notary public, as required by
state law, and admitted at trial in lieu of the analysts’ testimony.
(Melendez–Diaz, supra, 557 U.S. at p. 308.) The high court
reasoned that the certificates were “quite plainly affidavits,” and
“are functionally identical to live, in-court testimony, doing
‘precisely what a witness does on direct examination.’ ” (Id. at
pp. 310–311). The high court concluded: “[U]nder our decision in
Crawford the analysts’ affidavits were testimonial statements,
and the analysts were ‘witnesses’ for purposes of the Sixth
Amendment.” (Id. at p. 311.)
In Bullcoming, an analyst tested the blood sample of an
alleged drunk driver. (Bullcoming, supra, 564 U.S. at p. 651.) In
his lab report, the analyst attested that he performed the test
using normal protocol and signed the report, and the report was
admitted into evidence through a surrogate analyst “who was
familiar with the laboratory’s testing procedures, but had neither
participated in nor observed the test on [the defendant’s] blood
sample.” (Ibid.) Bullcoming rejected the argument that an
opportunity to cross-examine the surrogate analyst satisfied
Crawford. (Id. at p. 652.) In doing so, the high court rejected the
New Mexico Supreme Court’s conclusion that the report merely
set forth a machine-generated result, observing that the testing
analyst reported several facts relating to past events and human
actions, as opposed to machine-produced data, and the analyst’s
statements were “meet for cross-examination.” (Id. at pp. 659-
660.) Bullcoming also rejected the claim that the report was
12
nontestimonial: Even though the report was not a formal
affidavit, it was a sufficiently formal and official document
“created solely for an ‘evidentiary purpose,’ . . . made in aid of a
police investigation, [and so] ranks as testimonial.” (Id. at
p. 664.)
Next, in Williams, supra, 567 U.S. 50, 57, at issue was a
police forensic biologist’s testimony that a DNA profile produced
by a Maryland laboratory was derived from semen on vaginal
swabs taken from the rape victim, and that the profile matched a
DNA profile derived from a sample of the defendant’s blood
produced by the police laboratory. (Id. at p. 56 (plur. opn. of
Alito, J.).) The plurality opinion by Justice Alito concluded, based
on two alternative grounds, that the expert testimony did not
violate the Confrontation Clause. First, the plurality reasoned,
the testimony regarding the Maryland laboratory’s report on the
DNA profile was admitted not for its truth, but only for the
limited purpose of explaining the basis of the police biologist’s
independent conclusion, based on her expertise, that the
defendant’s DNA matched the DNA in the semen found on the
vaginal swabs. (Id. at pp. 57–58.) Alternatively, the plurality
reasoned, there was no constitutional violation because the
Maryland laboratory’s report was not “for the primary purpose of
accusing a targeted individual.” (Id. at pp. 83–86.) In a
concurring opinion, Justice Thomas agreed that the expert
testimony did not violate the Confrontation Clause, but for a
completely different reason: The Maryland laboratory report
“lack[ed] the solemnity of an affidavit or deposition” and was
13
therefore not “testimonial.” (Id. at p. 111 (conc. opn. of Thomas,
J.).)
Defendant’s Crawford challenge lacks merit. His argument
is that the court’s failure to order production of the source code
violated the Sixth Amendment as interpreted by Crawford
because the source code is testimonial hearsay that Kidwell
disclosed through her testimony regarding the likelihood ratios.
Defendant misunderstands Crawford. Crawford held that the
confrontation clause bars the admission of testimonial hearsay
statements against a defendant at trial unless the declarant is
unavailable and the defendant had a prior opportunity to cross-
examine that person or the declarant appears at trial.
(Crawford, supra, 541 U.S. at pp. 53, 59 & fn. 9.) Crawford is
“concerned solely with [the admission at trial of] hearsay
statements that are testimonial” (People v. Cage (2007)
40 Cal.4th 965, 981), and it requires a trial objection. (People v.
Amezcua and Flores (2019) 6 Cal.5th 886, 911 [failure to object to
offending testimony forfeits Crawford claim]; Evid. Code, § 353.)
Here, defendant asked the court during trial to inform the jury
that the court had denied defendant’s request for the source code,
but he did not move to strike any of Kidwell’s testimony based on
the theory that the TrueAllele source code was testimonial
hearsay that Kidwell improperly conveyed to the jury.
Defendant’s pretrial motion and motion in limine raised a
discovery issue and sought production of the source code, but
Crawford is not a mechanism for obtaining discovery.
Defendant’s contention that the failure to order production of
14
TrueAllele’s source code violated the confrontation clause under
Crawford thus fails.
Nonetheless, even assuming the trial court committed error
in failing to order disclosure of TrueAllele’s source code, any such
error was harmless beyond a reasonable doubt given the
overwhelming evidence of defendant’s guilt unrelated to
TrueAllele. (See Chapman v. California (1967) 386 U.S. 18, 24;
People v. Jennings (2010) 50 Cal.4th 616, 652 [finding alleged
Crawford error harmless beyond a reasonable doubt under
Chapman in light of other overwhelming circumstantial
evidence]; People v. Bell (2020) 47 Cal.App.5th 153, 196–197
[finding Crawford error harmless where other evidence
overwhelmingly proved facts at issue].) The victim’s body was
found in a small bedroom in defendant’s parents’ house where
defendant stayed. Defendant and the victim were together at the
house the day before the victim’s was found dead. Defendant’s
parents were away when defendant’s brother found defendant
sleeping in the bedroom where the victim’s body lay covered in
bags and a blanket. Some of the blood on the garbage bag
covering the victim was still wet when police found the body, an
investigating office confirmed there was both dry and wet blood
at the scene when the body was found, and there was blood on
the bedroom floor and furniture. When the police arrived at the
house, announced their presence, and ordered defendant to come
out, he hid for over fifteen minutes while police searched the
home. When police finally found defendant hiding in a closet, he
had fresh injuries and he lied to police about his name. Further,
15
DNA evidence unrelated to TrueAllele established that a hair
found on the victim’s elbow belonged to defendant.
III. The Claim of Error under Davis
Restrictions imposed on the cross-examination designed to
test witness credibility can, in certain instances, result in
confrontation clause violations. For example, in Davis, supra,
415 U.S. 308, the defendant was charged with burglarizing a bar
and stealing its safe, and a crucial witness testified that he saw
the defendant with a crowbar near the place where the empty
safe was discovered. (Id. at pp. 309–310.) At the time of trial,
the witness was on juvenile probation for burglarizing two cabins.
(Id. at pp. 310–311.) Despite the defendant’s argument that he
needed to probe the witness’s probation status on cross-
examination to reveal the witness’s possible bias in cooperating
with the police, the trial court refused to permit counsel to
inquire into the subject. (Id. at p. 311.) Davis held that, under
the confrontation clause, a defendant could not be prevented at
trial from cross-examining a crucial witness for bias, even though
the questions called for information made confidential by state
law. (Id. at pp. 317–318.) The test used to assess whether a
court’s limitation on cross-examination pertaining to the
credibility or bias of a witness violates the confrontation clause is
whether “a reasonable jury might have received a significantly
different impression of the witness’s credibility had the excluded
cross-examination been permitted.” (People v. Quartermain
(1997) 16 Cal.4th 600, 624.)
16
Here, there was no confrontation clause violation under
Davis even if we were to accept defendant’s seemingly tenuous
contention that a defendant has a Sixth Amendment right to
pretrial disclosure of privileged information purportedly needed
for effective cross-examination. (See People v. Hammon (1997)
15 Cal.4th 1117, 1124, 1128 [reviewing high court jurisprudence
and finding no pretrial right to disclosure of privileged
information under Sixth Amendment].) Defendant argued in his
opening brief that the source code was required for “meaningful
cross-examination of the prosecution witnesses relying on
evidence derived from [TrueAllele].” Kidwell was the
prosecution’s witness, and, as defendant concedes many times in
his reply brief, Kidwell “lacked direct knowledge of the source
code and thus [did] not know the assumptions or biases of the
programmer who wrote it.” Nothing prevented defendant from
cross-examining Kidwell on the fact that she lacked any
knowledge of the source code, nor did anything prevent defendant
from seeking to strike Kidwell’s TrueAllele-related testimony
based on his claimed lack of ability to cross-examine her
effectively. Defendant admits, however, that because of Kidwell’s
lack of personal knowledge, she “could not be cross-examined
about any potential errors or biases that may have influenced the
results she testified to regarding the likelihood ratios.” Thus,
defendant has not shown that the prohibited cross-examination
17
would have produced a significantly different impression of the
credibility of Kidwell’s testimony.3
DISPOSITION
The judgment is affirmed.
BROWN, J.
WE CONCUR:
STREETER, ACTING P. J.
GOLDMAN, J.
People v. Perez (A165848)
3We note that defendant’s trial counsel was well aware
that Dr. Perlin wrote the TrueAllele source code, and the record
does not reflect any effort to subpoena Dr. Perlin. Instead,
defendant argued to the trial court that he was entitled to
disclosure of the source code to put on a defense and to call his
own expert to testify regarding the bias and assumptions therein.
We express no opinion on the merits of such argument because
defendant does not pursue it on appeal. We similarly express no
opinion on the question of whether a defendant has a right to
discover the source code for probabilistic genotyping software for
purposes of conducting a hearing under People v. Kelly (1976)
17 Cal.3d 24 (see State v. Pickett (N.J. App. 2021) 466 N.J. Super.
270 [246 A.3d 279]), as that issue is not before us.
18