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SUPREME COURT OF THE UNITED STATES
_________________
No. 10–8505
_________________
SANDY WILLIAMS, PETITIONER v. ILLINOIS
on writ of certiorari to the supreme court of
illinois
[June 18, 2012]
Justice Alito announced the judgment of the
Court and delivered an opinion, in which The Chief Justice, Justice
Kennedy, and Justice Breyer join.
In this case, we decide whether Crawford v.
Washington,
541 U.S.
36, 50 (2004) , precludes an expert witness from testifying in
a manner that has long been allowed under the law of evidence.
Specifically, does Crawford bar an expert from expressing an
opinion based on facts about a case that have been made known to
the expert but about which the expert is not competent to testify?
We also decide whether Crawford substantially impedes the ability
of prosecutors to introduce DNA evidence and thus may effectively
relegate the prosecution in some cases to reliance on older, less
reliable forms of proof.
In petitioner’s bench trial for rape, the
prosecution called an expert who testified that a DNA profile
produced by an outside laboratory, Cellmark, matched a profile
produced by the state police lab using a sample of petitioner’s
blood. On direct examination, the expert testified that Cellmark
was an accredited laboratory and that Cellmark provided the police
with a DNA profile. The expert also explained the notations on
documents admitted as business records, stating that, according to
the records, vaginal swabs taken from the victim were sent to and
received back from Cellmark. The expert made no other statement
that was offered for the purpose of identifying the sample of
biological material used in deriving the profile or for the purpose
of establishing how Cellmark handled or tested the sample. Nor did
the expert vouch for the accuracy of the profile that Cellmark
produced. Nevertheless, petitioner contends that the expert’s
testimony violated the Confrontation Clause as interpreted in
Crawford.
Petitioner’s main argument is that the expert
went astray when she referred to the DNA profile provided by
Cellmark as having been produced from semen found on the victim’s
vaginal swabs. But both the Illinois Appellate Court and the
Illinois Supreme Court found that this statement was not admitted
for the truth of the matter asserted, and it is settled that the
Confrontation Clause does not bar the admission of such statements.
See id., at 59–60, n. 9 (citing Tennessee v. Street,
471
U.S. 409 (1985) ). For more than 200 years, the law of evidence
has permitted the sort of testimony that was given by the ex- pert
in this case. Under settled evidence law, an expert may express an
opinion that is based on facts that the expert assumes, but does
not know, to be true. It is then up to the party who calls the
expert to introduce other evidence establishing the facts assumed
by the expert. While it was once the practice for an expert who
based an opinion on assumed facts to testify in the form of an an-
swer to a hypothetical question, modern practice does not demand
this formality and, in appropriate cases, permits an expert to
explain the facts on which his or her opinion is based without
testifying to the truth of those facts. See Fed. Rule Evid. 703.
That is precisely what occurred in this case, and we should not
lightly “swee[p] away an accepted rule governing the admission of
scientific evidence.” Melendez-Diaz v. Massachusetts,
557
U.S. 305, 330 (2009) (Kennedy, J., dissenting).
We now conclude that this form of expert
testimony does not violate the Confrontation Clause because that
provision has no application to out-of-court statements that are
not offered to prove the truth of the matter asserted. When an
expert testifies for the prosecution in a criminal case, the
defendant has the opportunity to cross-examine the expert about any
statements that are offered for their truth. Out-of-court
statements that are related by the expert solely for the purpose of
explaining the assumptions on which that opinion rests are not
offered for their truth and thus fall outside the scope of the
Confrontation Clause. Applying this rule to the present case, we
conclude that the expert’s testimony did not violate the Sixth
Amendment.
As a second, independent basis for our decision,
we also conclude that even if the report produced by Cellmark had
been admitted into evidence, there would have been no Confrontation
Clause violation. The Cellmark report is very different from the
sort of extrajudicial statements, such as affidavits, depositions,
prior testimony, and confessions, that the Confrontation Clause was
originally understood to reach. The report was produced before any
suspect was identified. The report was sought not for the purpose
of obtaining evidence to be used against petitioner, who was not
even under suspicion at the time, but for the purpose of finding a
rapist who was on the loose. And the profile that Cellmark provided
was not inherently inculpatory. On the contrary, a DNA profile is
evidence that tends to exculpate all but one of the more than 7
billion people in the world today. The use of DNA evidence to
exonerate persons who have been wrongfully accused or convicted is
well known. If DNA profiles could not be introduced without calling
the technicians who participated in the preparation of the profile,
economic pressures would encourage prosecutors to forgo DNA testing
and rely instead on older forms of evidence, such as eyewitness
identification, that are less reliable. See Perry v. New Hampshire,
565 U. S. ___ (2012). The Confrontation Clause does not
mandate such an undesirable development. This conclusion will not
prejudice any defendant who really wishes to probe the reliability
of the DNA testing done in a particular case because those who
participated in the testing may always be subpoenaed by the defense
and questioned at trial.
I
A
On February 10, 2000, in Chicago, Illinois, a
young woman, L. J., was abducted while she was walking home
from work. The perpetrator forced her into his car and raped her,
then robbed her of her money and other personal items and pushed
her out into the street. L. J. ran home and reported the
attack to her mother, who called the police. An ambulance took
L. J. to the hospital, where doctors treated her wounds and
took a blood sample and vaginal swabs for a sexual-assault kit. A
Chicago Police detective collected the kit, labeled it with an
inventory number, and sent it under seal to the Illinois State
Police (ISP) lab.
At the ISP lab, a forensic scientist received
the sealed kit. He conducted a chemical test that confirmed the
presence of semen on the vaginal swabs, and he then resealed the
kit and placed it in a secure evidence freezer.
During the period in question, the ISP lab often
sent biological samples to Cellmark Diagnostics Laboratory in
Germantown, Maryland, for DNA testing. There was evidence that the
ISP lab sent L. J.’s vaginal swabs to Cellmark for testing and
that Cellmark sent back a report containing a male DNA profile
produced from semen taken from those swabs. At this time,
petitioner was not under suspicion for L. J.’s rape.
Sandra Lambatos, a forensic specialist at the
ISP lab, conducted a computer search to see if the Cellmark profile
matched any of the entries in the state DNA database. The computer
showed a match to a profile produced by the lab from a sample of
petitioner’s blood that had been taken after he was arrested on
unrelated charges on August 3, 2000.
On April 17, 2001, the police conducted a lineup
at which L. J. identified petitioner as her assailant.
Petitioner was then indicted for aggravated criminal sexual
assault, aggravated kidnaping, and aggravated robbery. In lieu of a
jury trial, petitioner chose to be tried before a state judge.
B
Petitioner’s bench trial began in April 2006.
In open court, L. J. again identified petitioner as her
attacker. The State also offered three expert forensic witnesses to
link petitioner to the crime through his DNA. First, Brian Hapack,
an ISP forensic scientist, testified that he had confirmed the
presence of semen on the vaginal swabs taken from L. J. by
performing an acid phosphatase test. After performing this test, he
testified, he resealed the evidence and left it in a secure freezer
at the ISP lab.
Second, Karen Abbinanti, a state forensic
analyst, testified that she had used Polymerase Chain Reaction
(PCR) and Short Tandem Repeat (STR) techniques to develop a DNA
profile from a blood sample that had been drawn from petitioner
after he was arrested in August 2000. She also stated that she had
entered petitioner’s DNA profile into the state forensic
database.
Third, the State offered Sandra Lambatos as an
expert witness in forensic biology and forensic DNA analysis. On
direct examination, Lambatos testified about the general process of
using the PCR and STR techniques to generate DNA profiles from
forensic samples such as blood and semen. She then described how
these DNA profiles could be matched to an individual based on the
individual’s unique genetic code. In making a comparison between
two DNA profiles, Lambatos stated, it is a “commonly accepted”
practice within the scientific community for “one DNA expert to
rely on the records of another DNA expert.” App. 51. Lambatos also
testified that Cellmark was an “accredited crime lab” and that, in
her experience, the ISP lab routinely sent evidence samples via
Federal Express to Cellmark for DNA testing in order to expedite
the testing process and to “reduce [the lab’s] backlog.” Id., at
49–50. To keep track of evidence samples and preserve the chain of
custody, Lambatos stated, she and other analysts relied on sealed
shipping containers and labeled shipping manifests, and she added
that experts in her field regularly relied on such protocols. Id.,
at 50–51.
Lambatos was shown shipping manifests that were
admitted into evidence as business records, and she explained what
they indicated, namely, that the ISP lab had sent L. J.’s
vaginal swabs to Cellmark, and that Cellmark had sent them back,
along with a deduced male DNA profile. Id., at 52–55. The
prosecutor asked Lambatos whether there was “a computer match”
between “the male DNA profile found in semen from the vaginal swabs
of [L. J.]” and “[the] male DNA profile that had been
identified” from petitioner’s blood sample. Id., at 55.
The defense attorney objected to this question
for “lack of foundation,” arguing that the prosecution had offered
“no evidence with regard to any testing that’s been done to
generate a DNA profile by another lab to be testified to by this
witness.” Ibid.
The prosecutor responded: “I‘m not getting at
what another lab did.” Id., at 56. Rather, she said, she was simply
asking Lambatos about “her own testing based on [DNA] information”
that she had received from Cellmark. Ibid. The trial judge agreed,
noting, “If she says she didn’t do her own testing and she relied
on a test of another lab and she’s testifying to that, we will see
what she’s going to say.” Ibid.
The prosecutor then proceeded, asking Lambatos,
“Did you compare the semen that had been identified by Brian Hapack
from the vaginal swabs of [L. J.] to the male DNA profile that
had been identified by Karen [Abbinanti] from the blood of
[petitioner]?” Ibid.
Lambatos answered “Yes.” Ibid. Defense counsel
lodged an objection “to the form of the question,” but the trial
judge overruled it. Ibid. Lambatos then testified that, based on
her own comparison of the two DNA profiles, she “concluded that
[petitioner] cannot be excluded as a possible source of the semen
identified in the vaginal swabs,” and that the probability of the
profile’s appearing in the general population was “1 in 8.7
quadrillion black, 1 in 390 quadrillion white, or 1 in 109
quadrillion Hispanic unrelated individuals.” Id., at 57. Asked
whether she would “call this a match to [petitioner],” Lambatos
answered yes, again over defense counsel’s objection. Id., at
58.
The Cellmark report itself was neither admitted
into evidence nor shown to the factfinder. Lambatos did not quote
or read from the report; nor did she identify it as the source of
any of the opinions she expressed.
On cross-examination, Lambatos confirmed that
she did not conduct or observe any of the testing on the vaginal
swabs, and that her testimony relied on the DNA profile produced by
Cellmark. Id., at 59. She stated that she trusted Cellmark to do
reliable work because it was an accredited lab, but she admitted
she had not seen any of the calibrations or work that Cellmark had
done in deducing a male DNA profile from the vaginal swabs. Id., at
59–62.
Asked whether the DNA sample might have been
degraded before Cellmark analyzed it, Lambatos answered that, while
degradation was technically possible, she strongly doubted it had
occurred in this case. She gave two reasons. First, the ISP lab
likely would have noticed the degradation before sending the
evidence off to Cell- mark. Second, and more important, Lambatos
also noted that the data making up the DNA profile would ex- hibit
certain telltale signs if it had been deduced from a degraded
sample: The visual representation of the DNA sequence would exhibit
“specific patterns” of degradation, and she “didn’t see any
evidence” of that from looking at the profile that Cellmark
produced. Id., at 81–82.
When Lambatos finished testifying, the defense
moved to exclude her testimony “with regards to testing done by
[Cellmark]” based on the Confrontation Clause. Id., at 90. Defense
counsel argued that there was “no evidence with regards to
. . . any work done by [Cellmark] to justify testimony
coming into this case with regard to their analysis.” Ibid. Thus,
while defense counsel objected to and sought the exclusion of
Lambatos’ testimony insofar as it implicated events at the Cellmark
lab, defense counsel did not object to or move for the exclusion of
any other portion of Lambatos’ testimony, including statements
regarding the contents of the shipment sent to or received back
from Cellmark. See id., at 55, 56, 90. See also 385 Ill. App. 3d
359, 367–368, 895 N.E.2d 961, 968 (2008) (chain-of-custody argument
based on shipping manifests waived).
The prosecution responded that petitioner’s
Confrontation Clause rights were satisfied because he had the
opportunity to cross-examine the expert who had testified that
there was a match between the DNA profiles produced by Cellmark and
Abbinanti. App. 91. Invoking Illinois Rule of Evidence 703, [
1 ] the prosecutor argued that
an expert is allowed to disclose the facts on which the expert’s
opinion is based even if the expert is not competent to testify to
those underlying facts. She further argued that any deficiency in
the foundation for the expert’s opinion “[d]oesn’t go to the
admissibility of [that] testi- mony,” but instead “goes to the
weight of the testimony.” App. 91.
The trial judge agreed with the prosecution and
stated that “the issue is . . . what weight do you
give the test, not do you exclude it.” Id., at 94. Accordingly, the
judge stated that he would not exclude Lambatos’ testimony, which
was “based on her own independent testing of the data received from
[Cellmark].” Id., at 94–95 (alteration in original).
The trial court found petitioner guilty of the
charges against him. The state court of appeals affirmed in
relevant part, concluding that Lambatos’ testimony did not violate
petitioner’s confrontation rights because the Cell- mark report was
not offered into evidence to prove the truth of the matter it
asserted. See 385 Ill. App. 3d, at 369, 895
N. E. 2d, at 969–970 (“Cellmark’s report was not offered
for the truth of the matter asserted; rather, it was offered to
provide a basis for Lambatos’ opinion”) The Supreme Court of
Illinois also affirmed. 238 Ill. 2d 125, 939 N.E.2d 268 (2010).
Under state law, the court noted, the Cellmark report could not be
used as substantive evidence. When Lambatos referenced the report
during her direct examination, she did so “for the limited purpose
of explaining the basis for [her expert opinion],” not for the
purpose of showing “the truth of the matter asserted” by the
report. Id., at 150, 939 N. E. 2d, at 282. Thus, the report
was not used to establish its truth, but only “to show the
underlying facts and data Lambatos used before rendering an expert
opinion.” Id., at 145, 939 N. E. 2d, at 279.
We granted certiorari. 564 U. S. ___
(2011).
II
A
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 wit- nesses against him.” Before Crawford, this Court took the
view that the Confrontation Clause did not bar the admission of an
out-of-court statement that fell within a firmly rooted exception
to the hearsay rule, see Ohio v. Roberts,
448 U.S.
56, 66 (1980) , but in Crawford, the Court adopted a
fundamentally new interpretation of the confronta- tion right,
holding that “[t]estimonial statements of witnesses absent from
trial [can be] admitted only where the declarant is unavailable,
and only where the defendant has had a prior opportunity to
cross-examine.” 541 U. S., at 59. Crawford has resulted in a
steady stream of new cases in this Court. See Bullcoming v. New
Mexico, 564 U. S. ___ (2011); Michigan v. Bryant, 562
U. S. ___ (2011); Melendez-Diaz,
557 U.S.
305 ; Giles v. California,
554 U.S.
353 (2008) ; Indiana v. Edwards,
554 U.S.
164 (2008) ; Davis v. Washington,
547
U.S. 813 (2006) .
Two of these decisions involved scientific
reports. In Melendez-Diaz, the defendant was arrested and charged
with distributing and trafficking in cocaine. At trial, the
prosecution introduced bags of a white powdery substance that had
been found in the defendant’s possession. The trial court also
admitted into evidence three “certificates of analysis” from the
state forensic laboratory stating that the bags had been “examined
with the following results: The substance was found to contain:
Cocaine.” 557 U. S., at 308 (internal quotation marks
omitted).
The Court held that the admission of these
certificates, which were executed under oath before a notary,
violated the Sixth Amendment. They were created for “the sole
purpose of providing evidence against a defendant,” id., at 323,
and were “ ‘quite plainly affidavits,’ ” id., at 330
(Thomas, J., concurring). The Court emphasized that the
introduction of the report to prove the nature of the substance
found in the defendant’s possession was tantamount to “live,
in-court testimony” on that critical fact and that the certificates
did “precisely what a witness does on direct examination.” Id., at
311 (internal quotation marks omitted). There was no doubt that the
certificates were used to prove the truth of the matter they
asserted. Under state law, “the sole purpose of the affidavits was
to provide prima facie evidence of the composition, quality, and
the net weight of the analyzed substance.” Ibid. (internal
quotation marks omitted and emphasis deleted). On these facts, the
Court said, it was clear that the certif- icates were “testimonial
statements” that could not be introduced unless their authors were
subjected to the “ ‘cru- cible of cross-examination.’ ”
Id., at 311, 317 (quoting Crawford, supra, at 61).
In Bullcoming, we held that another scientific
report could not be used as substantive evidence against the de-
fendant unless the analyst who prepared and certified the report
was subject to confrontation. The defendant in that case had been
convicted of driving while intoxicated. At trial, the court
admitted into evidence a forensic report certifying that a sample
of the defendant’s blood had an alcohol concentration of 0.21 grams
per hundred milli- liters, well above the legal limit. Instead of
calling the analyst who signed and certified the forensic report,
the prosecution called another analyst who had not performed or
observed the actual analysis, but was only familiar with the
general testing procedures of the laboratory. The Court declined to
accept this surrogate testimony, despite the fact that the
testifying analyst was a “knowledgeable representative of the
laboratory” who could “explain the lab’s processes and the details
of the report.” 564 U. S., at ___ (Kennedy, J., dissenting)
(slip op., at 1). The Court stated simply: “The accused’s right is
to be confronted with the analyst who made the certification.” Id.,
at ___ (slip op., at 2).
Just as in Melendez-Diaz, the forensic report
that was “introduce[d]” in Bullcoming “contain[ed] a testimonial
certification, made in order to prove a fact at a criminal trial.”
564 U. S., at ___–___ (slip op., at 7–8). The report was
signed by the nontestifying analyst who had authored it, stating,
“I certify that I followed the procedures set out on the reverse of
this report, and the statements in this block are correct. The
concentration of alcohol in this sample is based on the grams of
alcohol in one hundred milliliters of blood.” App. in Bullcoming,
O. T. 2010, No. 09–10876, p. 62. Critically, the
report was introduced at trial for the substantive purpose of
proving the truth of the matter asserted by its out-of-court
author—namely, that the defendant had a blood-alcohol level of
0.21. This was the central fact in question at the defendant’s
trial, and it was dispositive of his guilt.
In concurrence, Justice Sotomayor highlighted
the im- portance of the fact that the forensic report had been
admitted into evidence for the purpose of proving the truth of the
matter it asserted. She emphasized that “this [was] not a case in
which an expert witness was asked for his independent opinion about
underlying testimonial reports that were not themselves admitted
into evidence.” 564 U. S., at ___ (slip op., at 6) (opinion
concurring in part) (citing Fed. Rule Evid. 703). “We would face a
different question,” she observed, “if asked to determine the
constitutionality of allowing an expert witness to discuss others’
testimonial statements if the testimonial statements were not
themselves admitted as evidence.” Id., at ___ (slip op., at 6).
We now confront that question.
B
It has long been accepted that an expert
witness may voice an opinion based on facts concerning the events
at issue in a particular case even if the expert lacks first-hand
knowledge of those facts.
At common law, courts developed two ways to deal
with this situation. An expert could rely on facts that had already
been established in the record. But because it was not always
possible to proceed in this manner, and because record evidence was
often disputed, courts developed the alternative practice of
allowing an expert to testify in the form of a “hypothetical
question.” Under this approach, the expert would be asked to assume
the truth of certain factual predicates, and was then asked to
offer an opinion based on those assumptions. See 1 K. Broun,
McCormick on Evidence §14, p. 87 (6th ed. 2006); 1 J. Wigmore,
Evidence §677, p. 1084 (2d ed. 1923) (“If the witness is skilled
enough, his opinion may be adequately obtained upon hypothetical
data alone; and it is immate- rial whether he has ever seen the
person, place or thing in question” (citation omitted)). The truth
of the premises could then be established through independent
evidence, and the factfinder would regard the expert’s testimony to
be only as credible as the premises on which it was based.
An early example of this approach comes from the
English case of Beckwith v. Sydebotham, 1 Camp. 116, 170 Eng. Rep.
897 (K. B. 1807), where a party sought to prove the
seaworthiness of a ship, the Earl of Wycombe, by calling as
witnesses “several eminent surveyors of ships who had never seen
the ‘Earl of Wycombe.’ ” Ibid. The opposing party objected to
the testimony because it relied on facts that were not known to be
true, but the judge disagreed. Because the experts were “peculiarly
ac- quainted” with “a matter of skill or science,” the judge said,
the “jury might be assisted” by their hypothetical opinion based on
certain assumed facts. Id., at 117, 170 Eng. Rep., at 897. The
judge acknowledged the danger of the jury’s being unduly prejudiced
by wrongly assuming the truth of the hypothetical facts, but the
judge noted that the experts could be asked on cross-examination
what their opinion of the ship’s seaworthiness would be if
different hypothetical facts were assumed. If the party that had
called the experts could not independently prove the truth of the
premises they posited, then the experts’ “opinion might not go for
much; but still it was admissible evidence.” Ibid.
There is a long tradition of the use of
hypothetical questions in American courts. In 1887, for example,
this Court indicated its approval of the following jury
instruction:
“As to the questions, you must understand
that they are not evidence; they are mere statements to these
witnesses . . . and, upon the hypothesis or assumption of
these questions the witnesses are asked to give their [opinion].
You must readily see that the value of the answers to these
questions depends largely, if not wholly, upon the fact whether the
statements made in these questions are sustained by the proof. If
the statements in these questions are not supported by the proof,
then the answers to the questions are entitled to no weight,
because based upon false assumptions or statements of facts.”
Forsyth v. Doolittle,
120 U.S.
73 (internal quotation marks omitted).
Modern rules of evidence continue to permit
experts to express opinions based on facts about which they lack
personal knowledge, but these rules dispense with the need for
hypothetical questions. Under both the Illinois and the Federal
Rules of Evidence, an expert may base an opinion on facts that are
“made known to the expert at or before the hearing,” but such
reliance does not constitute admissible evidence of this underlying
information. Ill. Rule Evid. 703; Fed. Rule Evid. 703. Accordingly,
in jury trials, both Illinois and federal law generally bar an
expert from disclosing such inadmissible evidence. [
2 ] In bench trials, however, both the
Illinois and the Federal Rules place no restriction on the
revelation of such information to the factfinder. When the judge
sits as the trier of fact, it is presumed that the judge will
understand the limited reason for the disclosure of the underlying
inadmissible information and will not rely on that information for
any improper purpose. As we have noted, “[i]n bench trials, judges
routinely hear inadmissible evidence that they are presumed to
ignore when making decisions.” Harris v. Rivera,
454 U.S.
339, 346 (1981) (per curiam). There is a “well-established
presumption” that “the judge [has] adhered to basic rules of
procedure,” when the judge is acting as a factfinder. Id., at
346–347 (emphasis added). See also Gentile v. State Bar of Nev.,
501 U.S.
1030, 1078 (1991) (Rehnquist, C. J., dissenting).
This feature of Illinois and federal law is
important because Crawford, while departing from prior
Confrontation Clause precedent in other respects, took pains to
reaffirm the proposition that the Confrontation Clause “does not
bar the use of testimonial statements for purposes other than
establishing the truth of the matter asserted.” 541 U. S., at
59–60, n. 9 (citing Tennessee v. Street,
471
U.S. 409 ). In Street, the defendant claimed that the police
had coerced him into adopting the confession of his alleged
accomplice. The prosecution sought to rebut this claim by showing
that the defendant’s confession differed significantly from the
accomplice’s. Although the accomplice’s confession was clearly a
testimonial statement, the Court held that the jurors could hear it
as long as they were instructed to consider that confession not for
its truth, but only for the “distinctive and limited purpose” of
comparing it to the defendant’s confession, to see whether the two
were identical. Id., at 417.
III
A
In order to assess petitioner’s Confrontation
Clause argument, it is helpful to inventory exactly what Lambatos
said on the stand about Cellmark. She testified to the truth of the
following matters: Cellmark was an accredited lab, App. 49; the ISP
occasionally sent forensic samples to Cellmark for DNA testing,
ibid.; according to shipping manifests admitted into evidence, the
ISP lab sent vaginal swabs taken from the victim to Cellmark and
later received those swabs back from Cellmark, id., at 52–55; and,
finally, the Cellmark DNA profile matched a profile produced by the
ISP lab from a sample of petitioner’s blood, id., at 55–56.
Lambatos had personal knowledge of all of these matters, and
therefore none of this testimony in- fringed petitioner’s
confrontation right.
Lambatos did not testify to the truth of any
other matter concerning Cellmark. She made no other reference to
the Cellmark report, which was not admitted into evidence and was
not seen by the trier of fact. Nor did she testify to anything that
was done at the Cellmark lab, and she did not vouch for the quality
of Cellmark’s work.
B
The principal argument advanced to show a
Confrontation Clause violation concerns the phrase that Lambatos
used when she referred to the DNA profile that the ISP lab received
from Cellmark. This argument is developed most fully in the
dissenting opinion, and therefore we refer to the dissent’s
discussion of this issue.
In the view of the dissent, the following is the
critical portion of Lambatos’ testimony, with the particular words
that the dissent finds objectionable italicized:
“Q Was there a computer match generated of the
male DNA profile found in semen from the vaginal swabs of [L.J.] to
a male DNA profile that had been identified as having originated
from Sandy Williams?
“A Yes, there was.” Post, at 7 (opinion of
Kagan, J.) (quoting App. 56; emphasis added).
According to the dissent, the italicized phrase
violated petitioner’s confrontation right because Lambatos lacked
personal knowledge that the profile produced by Cellmark was based
on the vaginal swabs taken from the victim, L. J. As the
dissent acknowledges, there would have been “nothing wrong with
Lambatos’s testifying that two DNA profiles—the one shown in the
Cellmark report and the one derived from Williams’s blood—matched
each other; that was a straightforward application of Lambatos’s
expertise.” Post, at 12. Thus, if Lambatos’ testimony had been
slightly modified as follows, the dissent would see no problem:
“Q Was there a computer match generated of the
male DNA profile produced by Cellmark found in semen from the
vaginal swabs of [L.J.] to a male DNA profile that had been
identified as having originated from Sandy Williams?
“A Yes, there was.” [
3 ]
The defect in this argument is that under
Illinois law (like federal law) it is clear that the putatively
offending phrase in Lambatos’ testimony was not admissible for the
purpose of proving the truth of the matter asserted—i.e., that the
matching DNA profile was “found in semen from the vaginal swabs.”
Rather, that fact was a mere premise of the prosecutor’s question,
and Lambatos simply assumed that premise to be true when she gave
her answer indicating that there was a match between the two DNA
profiles. There is no reason to think that the trier of fact took
Lambatos’ answer as substantive evidence to establish where the DNA
profiles came from.
The dissent’s argument would have force if
petitioner had elected to have a jury trial. In that event, there
would have been a danger of the jury’s taking Lambatos’ testimony
as proof that the Cellmark profile was derived from the sample
obtained from the victim’s vaginal swabs. Absent an evaluation of
the risk of juror confusion and careful jury instructions, the
testimony could not have gone to the jury.
This case, however, involves a bench trial and
we must assume that the trial judge understood that the portion of
Lambatos’ testimony to which the dissent objects was not admissible
to prove the truth of the matter asserted. [
4 ] The dissent, on the other hand, reaches the
truly remarkable conclusion that the wording of Lambatos’ testimony
confused the trial judge. Were it not for that wording, the
argument goes, the judge might have found that the prosecution
failed to introduce sufficient admissible evidence to show that the
Cellmark profile was derived from the sample taken from the victim,
and the judge might have disregarded the DNA evidence. This
argument reflects a profound lack of respect for the acumen of the
trial judge. [
5 ]
To begin, the dissent’s argument finds no
support in the trial record. After defense counsel objected to
Lambatos’ testimony, the prosecutor made clear that she was asking
Lambatos only about “her own testing based on [DNA] information”
that she had received from Cellmark. App. 56. Recognizing that
Lambatos’ testimony would carry weight only if the underlying
premises could be established, the judge noted that “the issue is
. . . what weight do you give the test [performed by
Lambatos], not do you exclude it.” Id., at 94. This echoes the old
statement in Beckwith that an expert’s opinion based on disputed
premises “might not go for much; but still it [is] admissible
evidence.” 1 Camp., at 117, 170 Eng. Rep., at 897. Both the
Illinois Appellate Court and the Illinois Supreme Court viewed the
record in this way, and we see no ground for disagreement. [
6 ]
Second, it is extraordinarily unlikely that any
trial judge would be confused in the way that the dissent posits.
That Lambatos was not competent to testify to the chain of custody
of the sample taken from the victim was a point that any trial
judge or attorney would immediately understand. Lambatos, after
all, had absolutely nothing to do with the collection of the sample
from the victim, its subsequent handling or preservation by the
police in Illinois, or its shipment to and receipt by Cellmark. No
trial judge would take Lambatos’ testimony as furnishing “the
missing link” in the State’s evidence regarding the identity of the
sample that Cellmark tested. See post, at 6 (opinion of Kagan,
J.).
Third, the admissible evidence left little room
for argument that the sample tested by Cellmark came from any
source other than the victim’s vaginal swabs. [
7 ] This is so because there is simply no
plausible explanation for how Cellmark could have produced a DNA
profile that matched Williams’ if Cellmark had tested any sample
other than the one taken from the victim. If any other items that
might have contained Williams’ DNA had been sent to Cellmark or
were otherwise in Cellmark’s possession, there would have been a
chance of a mix-up or of cross-contamination. See District
Attorney’s Office for Third Judicial Dist. v. Osborne, 557 U.S. 52,
80 (2009) (Alito, J., concurring). But there is absolutely nothing
to suggest that Cellmark had any such items. Thus, the fact that
the Cellmark profile matched Williams—the very man whom the victim
identified in a lineup and at trial as her at- tacker—was itself
striking confirmation that the sample that Cellmark tested was the
sample taken from the victim’s vaginal swabs. For these reasons, it
is fanciful to suggest that the trial judge took Lambatos’
testimony as providing critical chain-of-custody evidence.
C
Other than the phrase that Lambatos used in
referring to the Cellmark profile, no specific passage in the trial
record has been identified as violating the Confrontation Clause,
but it is nevertheless suggested that the State somehow introduced
“the substance of Cellmark’s report into evidence.” Post, at 8
(Kagan, J., dissenting). The main impetus for this argument appears
to be the (erroneous) view that unless the substance of the report
was sneaked in, there would be insufficient evidence in the record
on two critical points: first, that the Cellmark profile was based
on the semen in the victim’s vaginal swabs and, second, that
Cellmark’s procedures were reli- able. This argument is both
legally irrelevant for present purposes and factually
incorrect.
As to legal relevance, the question before us is
whether petitioner’s Sixth Amendment confrontation right was
violated, not whether the State offered sufficient foundational
evidence to support the admission of Lambatos’ opinion about the
DNA match. In order to prove these underlying facts, the
prosecution relied on circumstantial evidence, and the Illinois
courts found that this evidence was sufficient to satisfy state-law
requirements regarding proof of foundational facts. See 385 Ill.
App. 3d, at 366–368, 895 N. E. 2d, at 967–968; 238 Ill. 2d, at 138,
939 N. E. 2d, at 275. We cannot review that interpretation and
application of Illinois law. Thus, even if the record did not
contain any evidence that could rationally support a finding that
Cellmark produced a scientifically reliable DNA profile based on L.
J.’s vaginal swab, that would not establish a Confrontation Clause
violation. If there were no proof that Cellmark produced an
accurate profile based on that sample, Lambatos’ testimony
regarding the match would be irrelevant, but the Confrontation
Clause, as interpreted in Crawford, does not bar the admission of
irrelevant evidence, only testimonial statements by declarants who
are not subject to cross-examination. [
8 ]
It is not correct, however, that the trial
record lacks admissible evidence with respect to the source of the
sam- ple that Cellmark tested or the reliability of the Cell- mark
profile. As to the source of the sample, the State offered
conventional chain-of-custody evidence, namely, the testimony of
the physician who obtained the vaginal swabs, the testimony of the
police employees who handled and kept custody of that evidence
until it was sent to Cellmark, and the shipping manifests, which
provided evidence that the swabs were sent to Cellmark and then
returned to the ISP lab. In addition, as already discussed, the
match between the Cellmark profile and petitioner’s profile was
itself telling confirmation that the Cellmark profile was deduced
from the semen on the vaginal swabs.
This match also provided strong circumstantial
evidence regarding the reliability of Cellmark’s work. Assuming
(for the reasons discussed above) that the Cellmark profile was
based on the semen on the vaginal swabs, how could shoddy or
dishonest work in the Cellmark lab [
9 ] have resulted in the production of a DNA profile that
just so happened to match petitioner’s? If the semen found on the
vaginal swabs was not petitioner’s and thus had an en- tirely
different DNA profile, how could sloppy work in the Cellmark lab
have transformed that entirely different profile into one that
matched petitioner’s? And without access to any other sample of
petitioner’s DNA (and recall that petitioner was not even under
suspicion at this time), how could a dishonest lab technician have
substituted pe- titioner’s DNA profile? Under the circumstances of
this case, it was surely permissible for the trier of fact to infer
that the odds of any of this were exceedingly low.
This analysis reveals that much of the dissent’s
argument rests on a very clear error. The dissent argues that
Lambatos’ testimony could be “true” only if the predicate facts
asserted in the Cellmark report were true, and therefore Lambatos’
reference to the report must have been used for the purpose of
proving the truth of those facts. See post, at 10–11. But the truth
of Lambatos’ testimony, properly understood, was not dependent on
the truth of any predicate facts. Lambatos testified that two DNA
profiles matched. The correctness of this expert opinion, which the
defense was able to test on cross-examination, was not in any way
dependent on the origin of the samples from which the profiles were
derived. Of course, Lambatos’ opinion would have lacked probative
value if the prosecution had not introduced other evidence to
establish the provenance of the profiles, but that has nothing to
do with the truth of her testimony.
The dissent is similarly mistaken in its
contention that the Cellmark report “was offered for its truth
because that is all such ‘basis evidence’ can be offered for.”
Post, at 13; see also post, at 3 (Thomas, J., concurring in
judgment) (“[S]tatements introduced to explain the basis of an
expert’s opinion are not introduced for a plausible nonhearsay
purpose”). This view is directly contrary to the current version of
Rule 703 of the Federal Rules of Evidence, which this Court
approved and sent to Congress in 2000. Under that Rule, “basis
evidence” that is not admissible for its truth may be disclosed
even in a jury trial under appropriate circumstances. The purpose
for allowing this disclosure is that it may “assis[t] the jury to
evaluate the expert’s opinion.” Advisory Committee’s 2000 Notes on
Fed. Rule Evid. 703, 28 U. S. C. App., p. 361. The Rule
703 approach, which was controversial when adopted, [
10 ] is based on the idea that the
disclosure of basis evidence can help the factfinder understand the
expert’s thought process and determine what weight to give to the
expert’s opinion. For example, if the factfinder were to suspect
that the expert relied on factual premises with no support in the
record, or that the expert drew an unwarranted inference from the
premises on which the expert relied, then the probativeness or
credibility of the expert’s opinion would be seriously undermined.
The purpose of disclosing the facts on which the expert relied is
to allay these fears—to show that the expert’s reasoning was not
illogical, and that the weight of the expert’s opinion does not
depend on factual premises unsupported by other evidence in the
record—not to prove the truth of the underlying facts.
Perhaps because it cannot seriously dispute the
legit- imate nonhearsay purpose of illuminating the expert’s
thought process, the dissent resorts to the last-ditch argument
that, after all, it really does not matter whether Lambatos’
statement regarding the source of the Cellmark report was admitted
for its truth. The dissent concedes that “the trial judge might
have ignored Lambatos’s statement about the Cellmark report,” but
nonetheless maintains that “the admission of that statement
violated the Confrontation Clause even if the judge ultimately put
it aside.” Post, at 15, n. 2. But in a bench trial, it is not
necessary for the judge to stop and make a formal statement on the
record regarding the limited reason for which the testimony is
admitted. If the judge does not consider the testimony for its
truth, the effect is precisely the same. Thus, if the trial judge
in this case did not rely on the statement in question for its
truth, there is simply no way around the proviso in Crawford that
the Confrontation Clause applies only to out-of-court statements
that are “use[d]” to “establis[h] the truth of the matter
asserted.” 541 U. S., at 59–60, n. 9 (citing Street,
471
U.S. 409 ).
For all these reasons, we conclude that
petitioner’s Sixth Amendment confrontation right was not
violated.
D
This conclusion is entirely consistent with
Bullcoming and Melendez-Diaz. In those cases, the forensic reports
were introduced into evidence, and there is no question that this
was done for the purpose of proving the truth of what they
asserted: in Bullcoming that the defendant’s blood alcohol level
exceeded the legal limit and in Melendez- Diaz that the substance
in question contained cocaine. Nothing comparable happened here. In
this case, the Cellmark report was not introduced into evidence. An
expert witness referred to the report not to prove the truth of the
matter asserted in the report, i.e., that the report contained an
accurate profile of the perpetrator’s DNA, but only to establish
that the report contained a DNA profile that matched the DNA
profile deduced from petitioner’s blood. Thus, just as in Street,
the report was not to be considered for its truth but only for the
“distinctive and limited purpose” of seeing whether it matched
something else. 471 U. S., at 417. The relevance of the match
was then established by independent circumstantial evidence showing
that the Cellmark report was based on a forensic sample taken from
the scene of the crime.
Our conclusion will not open the door for the
kind of abuses suggested by some of petitioner’s amici and the
dissent. See post, at 10–11; Brief for Richard D. Friedman as
Amicus Curiae 20–21. In the hypothetical situations posited, an
expert expresses an opinion based on factual premises not supported
by any admissible evidence, and may also reveal the out-of-court
statements on which the expert relied. [
11 ] There are at least four safeguards to prevent
such abuses. First, trial courts can screen out experts who would
act as mere conduits for hearsay by strictly enforcing the
requirement that experts display some genuine “scientific,
technical, or other specialized knowledge [that] will help the
trier of fact to understand the evidence or to determine a fact in
issue.” Fed. Rule Evid. 702(a). Second, experts are generally
precluded from disclosing inadmissible evidence to a jury. See Fed.
Rule Evid. 703; People v. Pasch,
152 Ill. 2d 133, 175–176,
604 N.E.2d 294, 310–311 (1992). Third, if such evidence is
disclosed, the trial judges may and, under most circumstances,
must, instruct the jury that out-of-court statements cannot be
accepted for their truth, and that an expert’s opinion is only as
good as the independent evidence that establishes its underlying
premises. See Fed. Rules Evid. 105, 703; People v. Scott,
148 Ill. 2d 479, 527–528,
594 N.E.2d 217, 236–237 (1992). And fourth, if the prosecution
cannot muster any independent admissible evidence to prove the
foundational facts that are essential to the relevance of the
expert’s testimony, then the expert’s testimony cannot be given any
weight by the trier of fact. [
12 ]
IV
A
Even if the Cellmark report had been
introduced for its truth, we would nevertheless conclude that there
was no Confrontation Clause violation. The Confrontation Clause
refers to testimony by “witnesses against” an accused. Both the
noted evidence scholar James Henry Wigmore and Justice Harlan
interpreted the Clause in a strictly literal sense as referring
solely to persons who testify in court, but we have not adopted
this narrow view. It has been said that “[t]he difficulty with the
Wigmore-Harlan view in its purest form is its tension with much of
the apparent history surrounding the evolution of the right of
confrontation at common law.” White v. Illinois,
502 U.S.
346, 360 (1992) (Thomas, J., concurring). “[T]he principal evil
at which the Confrontation Clause was directed,” the Court
concluded in Crawford, “was the civil-law mode of criminal
procedure, and particularly its use of ex parte examinations as
evidence against the accused.” 541 U. S., at 50. “[I]n
England, pretrial examinations of suspects and witnesses by
government officials ‘were sometimes read in court in lieu of live
testimony.’ ” Bryant, 562 U. S., at ___ (slip op., at 6)
(quoting Crawford, supra, at 43). The Court has thus interpreted
the Confrontation Clause as prohibiting modern-day practices that
are tantamount to the abuses that gave rise to the recognition of
the confrontation right. But any further expansion would strain the
constitutional text.
The abuses that the Court has identified as
prompting the adoption of the Confrontation Clause shared the
following two characteristics: (a) they involved out-of-court
statements having the primary purpose of accusing a targeted
individual of engaging in criminal conduct and (b) they involved
formalized statements such as affidavits, depositions, prior
testimony, or confessions. In all but one of the post-Crawford
cases [
13 ] in which a
Confrontation Clause violation has been found, both of these
characteristics were present. See Bullcoming, 564 U. S., at
308 (slip op., at 3–4) (certified lab report having purpose of
showing that defendant’s blood-alcohol level exceeded legal limit);
Melendez-Diaz, 557 U. S., at 308 (certified lab report having
purpose of showing that substance connected to defendant contained
cocaine); Crawford, supra, at 38 (custodial statement made after
Miranda warnings that shifted blame from declarant to accused). [
14 ] The one exception
occurred in Hammon v. Indiana,
547
U.S. 813 –832 (2006), which was decided together with Davis v.
Washington, but in Hammon and every other post-Crawford case in
which the Court has found a violation of the confrontation right,
the statement at issue had the primary purpose of accusing a
targeted individual.
B
In Hammon, the one case in which an informal
statement was held to violate the Confrontation Clause, we
considered statements elicited in the course of police in-
terrogation. We held that a statement does not fall within the
ambit of the Clause when it is made “under circumstances
objectively indicating that the primary purpose of the
interrogation is to enable police assistance to meet an ongoing
emergency.” 547 U. S., at 822. In Bryant, another
police-interrogation case, we explained that a person who makes a
statement to resolve an ongoing emergency is not acting like a
trial witness because the declarant’s purpose is not to provide a
solemn declaration for use at trial, but to bring an end to an
ongoing threat. See 562 U. S., at ___, ___ (slip op., at 11,
14). We noted that “the prospect of fabrication . . . is
presumably significantly diminished” when a statement is made under
such circumstances, id., at ___ (slip op., at 14) and that
reliability is a salient characteristic of a statement that falls
outside the reach of the Confrontation Clause, id., at ___–___
(slip op., at 14–15). We emphasized that if a statement is not made
for “the primary purpose of creating an out-of-court substitute for
trial testimony,” its admissibility “is the concern of state and
federal rules of evidence, not the Confrontation Clause.” Id., at
___–___ (slip op., at 11–12).
In Melendez-Diaz and Bullcoming, the Court held
that the particular forensic reports at issue qualified as
testimonial statements, but the Court did not hold that all
forensic reports fall into the same category. Introduction of the
reports in those cases ran afoul of the Confrontation Clause
because they were the equivalent of affidavits made for the purpose
of proving the guilt of a particular criminal defendant at trial.
There was nothing resembling an ongoing emergency, as the suspects
in both cases had already been captured, and the tests in question
were relatively simple and can generally be performed by a single
analyst. In addition, the technicians who prepared the reports must
have realized that their contents (which reported an elevated
blood-alcohol level and the presence of an illegal drug) would be
incriminating.
C
The Cellmark report is very different. It
plainly was not prepared for the primary purpose of accusing a
targeted individual. In identifying the primary purpose of an
out-of-court statement, we apply an objective test. Bryant, 562
U. S., at ___ (slip op., at 13). We look for the primary
purpose that a reasonable person would have ascribed to the
statement, taking into account all of the surrounding
circumstances. Ibid.
Here, the primary purpose of the Cellmark
report, viewed objectively, was not to accuse petitioner or to
create evidence for use at trial. When the ISP lab sent the sample
to Cellmark, its primary purpose was to catch a dangerous rapist
who was still at large, not to obtain evidence for use against
petitioner, who was neither in custody nor under suspicion at that
time. Similarly, no one at Cellmark could have possibly known that
the profile that it produced would turn out to inculpate
petitioner—or for that matter, anyone else whose DNA profile was in
a law enforcement database. Under these circumstances, there was no
“prospect of fabrication” and no incentive to produce anything
other than a scientifi- cally sound and reliable profile. Id., at
___ (slip op., at 14).
The situation in which the Cellmark technicians
found themselves was by no means unique. When lab technicians are
asked to work on the production of a DNA profile, they often have
no idea what the consequences of their work will be. In some cases,
a DNA profile may provide powerful incriminating evidence against a
person who is identified either before or after the profile is
completed. But in others, the primary effect of the profile is to
exonerate a suspect who has been charged or is under investigation.
The technicians who prepare a DNA profile generally have no way of
knowing whether it will turn out to be incriminating or
exonerating—or both.
It is also significant that in many labs,
numerous technicians work on each DNA profile. See Brief for New
York County District Attorney’s Office et al. as Amici Curiae
6 (New York lab uses at least 12 technicians for each case); People
v. Johnson, 389 Ill. App. 3d 618, 627, 906 N.E.2d 70, 79 (2009)
(“[A]pproximately 10 Cellmark analysts were involved in the
laboratory work in this case”). When the work of a lab is divided
up in such a way, it is likely that the sole purpose of each
technician is simply to perform his or her task in accordance with
accepted procedures.
Finally, the knowledge that defects in a DNA
profile may often be detected from the profile itself provides a
further safeguard. In this case, for example, Lambatos testified
that she would have been able to tell from the profile if the
sample used by Cellmark had been degraded prior to testing. As
noted above, moreover, there is no real chance that “sample
contamination, sample switching, mislabeling, [or] fraud” could
have led Cellmark to produce a DNA profile that falsely matched
petitioner. Post, at 21 (Kagan, J., dissenting). At the time of the
testing, petitioner had not yet been identified as a suspect, and
there is no suggestion that anyone at Cellmark had a sample of his
DNA to swap in by malice or mistake. And given the complexity of
the DNA molecule, it is inconceivable that shoddy lab work would
somehow produce a DNA profile that just so happened to have the
precise genetic makeup of petitioner, who just so happened to be
picked out of a lineup by the victim. The prospect is beyond
fanciful.
In short, the use at trial of a DNA report
prepared by a modern, accredited laboratory “bears little if any
resemblance to the historical practices that the Confrontation
Clause aimed to eliminate.” Bryant, supra, at ___ (slip op., at 2)
(Thomas, J., concurring).
* * *
For the two independent reasons explained
above, we conclude that there was no Confrontation Clause violation
in this case. Accordingly, the judgment of the Supreme Court of
Illinois is
Affirmed.