63 A.3d 1033 | D.C. | 2013
After a jury trial, appellant Robert Young was convicted of kidnapping and rape based on an FBI examiner’s testimony that his DNA profile matched the DNA profile of the rapist. On appeal, Young argues that the trial court committed reversible error under the Confrontation Clause of the Sixth Amendment when it allowed the government to present this testimony without calling as witnesses the laboratory scientists who derived and identified the two DNA profiles and performed the calculations on which the testifying examiner based her conclusions. In addition, Young contends that the court abused its discretion in denying his motion to compel discovery of the frequency of profile matches and near-matches in the government’s DNA database. We agree with Young’s first claim but not his second.
I. Factual Background
A.
In the afternoon of October 11, 2006, Carmen Villatoro was assaulted in her apartment building in Northeast D.C. Her assailant, whom she did not know, dragged her down to the basement, forced her to perform oral sex, and attempted to penetrate her vaginally. After finding himself unable to penetrate her fully, he left.
Ms. Villatoro immediately went up to her apartment and spit the semen she had in her mouth into a tissue, which she tossed in a trash can. Her family called the police. Villatoro had avoided looking directly at her assailant’s face, but she was able to describe him to a detective as a six-foot-tall black man with big lips and thick eyebrows. She later added that he had a broken tooth. The police collected the contents of the trash can and other evidence from the scene of the crime. Villatoro was taken to a hospital, where a sexual assault nurse examined her and took swabs from her mouth and vagina. The swabs and the contents of the trash can were sent to an FBI laboratory in Quantico, Virginia, for DNA testing and analysis.
A team of scientists at the FBI lab reportedly derived a male DNA profile— the profile, presumably, of Villatoro’s attacker — from her vaginal swabs and entered it into the FBI’s database of offender DNA profiles. In November 2007, a CODIS
Prior to the start of his trial, Young moved the court pursuant to Criminal Rule 16
B.
The government presented its DNA evidence at Young’s trial through the testimony of a single witness: Rhonda Craig, the FBI examiner who had compared and matched the DNA profiles generated from the buccal sample and the crime scene evidence. Young objected that the admission of Craig’s testimony would violate his Sixth Amendment right to be confronted with the witnesses against him because she herself had not done the testing or produced those results. After hearing Craig’s testimony, the trial court overruled Young’s objection.
Craig was qualified as an expert in forensic serology and DNA analysis. She testified that she supervises five FBI ser-ologists and biologists who follow written testing procedures and National Quality Assurance Standards applicable to “all forensic DNA testing laboratories” in order to isolate DNA from evidentiary source materials and generate DNA profiles that she then compares and interprets.
Craig described the evidentiary submissions that the FBI laboratory received and tested for DNA in order to identify Villato-
Craig acknowledged in the course of her testimony that she did not personally perform the DNA testing and computer analysis that generated the DNA profiles she compared and the RMP she reported. Nor did Craig claim that she personally observed the receipt and handling of the evidence and the performance of the lab work preparatory to the DNA testing. Thus, when she informed the jury that the DNA profiles she examined were derived from the vaginal swabs and tissue furnished by Villatoro and the reference sample supplied by Young, Craig was not testifying from personal knowledge of those facts. Rather, she was relaying information provided by her subordinates through their documentation and identification of their work product. Similarly, in testifying to the RMP, Craig relayed information provided to her by the lab employee who ran the PopStats program. And in testifying to the sealed condition of the physical evidence when it was received by the lab, she relayed information recorded by the evidence control unit. In other words, all Craig could say from personal knowledge was that she compared electropherograms and they matched; she could not say from personal knowledge whose electrophero-grams they were or how they were derived.
In a post-verdict motion for a new trial, Young renewed Ms claim that Craig’s testimony was admitted in violation of the Confrontation Clause because it was
based on the work that other, non-testifying witnesses performed. Ms. Craig had no personal knowledge of the DNA extractions or analysis that occurred pri- or to her reviewing the computer generated data at the end of the process. Indeed, Ms. Craig had no personal knowledge of the random match probability calculation that formed the basis of her conclusion that Mr. Young was the source of the evidence sample DNA. Nevertheless, Ms. Craig repeatedly testified regarding work that others had done and conclusions that others had reached.
The court denied the motion in a written order, concluding that the Sixth Amendment “does not demand that a testifying expert perform the lab work herselfi;] rather an expert may testify about laboratory reports prepared by a different lab technician so long as the testifying expert performs an independent analysis of the data and reaches her own conclusions.”
II. Confrontation
A.
In Crawford v. Washington, the Supreme Court held that the Confrontation Clause of the Sixth Amendment bars the prosecution from introducing “testimonial” hearsay of an absent witness against a defendant at trial unless the witness is unavailable to testify and the defendant had a prior opportunity to cross-examine him.
The critical question in Confrontation Clause jurisprudence is the meaning of the term “testimonial.” The Supreme Court has declared that for a hearsay statement to be deemed “testimonial,” it must be “[a] solemn declaration or affirmation made for the purpose of establishing or proving some fact”
The Supreme Court is divided on whether, in addition to having a primarily evidentiary purpose, an out-of-court statement must meet any additional requirements in order to be deemed “testimonial.” The divisions, which date back to Crawford itself, were on display most recently in Williams v. Illinois,
The facts before the Court in Williams were similar, but not identical, to those in the present case. A woman in Illinois was kidnapped and raped. Vaginal swabs taken from her were submitted to an independent, private laboratory — Cellmark. In response, Cellmark produced a report transmitting a DNA profile that its analysts had developed from the swabs. A state police DNA analyst then searched the state’s database and found a matching profile, that of Williams. At trial, over Williams’s Confrontation Clause objection, the police analyst was permitted to testify that the DNA profile of Williams on file in the state database matched a male DNA profile Cellmark had created from semen in the victim’s vaginal swabs. (Cellmark’s written report, on which the analyst relied to give this testimony, was not itself introduced in evidence.) No witness having personal knowledge of Cellmark’s development of the putative offender’s DNA profile testified at trial.
On these facts, five Justices concluded that the Confrontation Clause was not violated by the state analyst’s testimony because the information in Cellmark’s report was not testimonial. The remaining Justices disagreed with that conclusion.
Four members of the Court, in a plurality opinion authored by Justice Alito, reasoned that the Cellmark report was not testimonial because it did not have “the primary purpose of accusing a targeted individual.”
Justice Thomas provided the fifth vote in support of the Williams judgment. He rejected what he called the plurality’s “new primary purpose test,” under which even a statement with a primarily eviden-tiary purpose is testimonial only if it is meant to incriminate a particular known individual, as “lacking] any grounding in constitutional text, in history, or in logic.”
Justice Kagan, in an opinion joined by Justices Scalia, Ginsburg, and Sotomayor, dissented. Like Justice Thomas, the dissenters rejected the plurality’s “targeted accusation” test on multiple grounds. Among other things, they noted that for Confrontation Clause purposes “it makes not a whit of difference whether, at the time of the laboratory test, the police already have a suspect” because “the typical problem with laboratory analyses — and the typical focus of cross-examination — has to do with careless or incompetent work, rather than with personal vendettas” or a particular analyst’s dishonesty.
For the dissenters, “adher[ing] to the simple rule” established by the Court’s Confrontation Clause precedents made Williams “an open-and-shut case.”
if a prosecutor wants to introduce the results of forensic testing into evidence, he must afford the defendant an opportunity to cross-examine an analyst responsible for the test. Forensic evidence is reliable only when properly produced, and the Confrontation Clause prescribes a particular method for determining whether that has happened.[36 ]
The fractured decision in Williams may be a harbinger of changes to come in the Supreme Court’s Confrontation Clause jurisprudence, but for now its force as precedent is uncertain because no rationale for the decision — not one of the three proffered tests for determining whether an extrajudicial statement is testimonial — attracted the support of a majority of the Justices. When “a majority of the Court expressly disagreed] with the rationale of the plurality,” a case is “of questionable precedential value.”
We do not get very far applying Marks here, for the two opinions of the Justices who concurred in the judgment in Williams lack the necessary common denominator. A statement could be made for the purpose of accusing a targeted individual and therefore be testimonial under Justice Alito’s test without being formal enough to satisfy Justice Thomas’s test. Conversely, a statement could be sufficiently formal to pass Justice Thomas’s test without being accusatory or targeted at a particular person. Thus, the rationales of Justice Alito’s opinion and Justice Thomas’s opinion are incommensurable — neither rationale is subsumed within the other or narrower than the other in any meaningful sense that we discern.
Appellant therefore contends that Williams is not binding precedent and that this court should ignore it and continue to adhere to Bullcoming, Melendez-Diaz, and our own cases that have applied the Confrontation Clause to forensic testimony. The government disagrees and argues that even if Williams lacks a rationale to which a majority of the Court subscribes, the case still must be taken by lower courts to govern the outcome of cases with analogous facts.
There is an intermediate position. By analogy to Marks, it can be argued that while Justice Alito’s rationale and Justice Thomas’s rationale may not be includible within each other, the different tests they utilize to determine whether a statement is testimonial are subsumed within and narrower than the dissenters’ test. That is so because Justice Alito and Justice Thomas each added an additional requirement to the basic “evidentiary purpose” test espoused by Justice Kagan. If the four-Justice plurality would deem a statement testimonial under the targeted accusation test, the four dissenting Justices surely would deem it testimonial under the broader evidentiary purpose test. Similarly, if Justice Thomas would deem a statement testimonial employing his formality criterion along with the evidentiary purpose test, the four dissenting Justices necessarily would deem it testimonial using the evi-dentiary purpose test alone. It therefore is logically coherent and faithful to the Justices’ expressed views to understand Williams as establishing — at a minimum— a sufficient, if not a necessary, criterion: a statement is testimonial at least when it passes the basic evidentiary purpose test
As we shall see, this is all we need to say about Williams (and its value as precedent) for purposes of deciding the present case.
B.
We now may turn to the dispositive question — whether the government’s expert witness at trial, FBI examiner Rhonda Craig, relayed testimonial hearsay concerning the DNA testing and analysis on which she based her opinion that appellant was Carmen Villatoro’s presumptive assailant. This is a question of law, as to which our review is de novo.
1. Hearsay
The government argues that Craig did not quote any particular hearsay statements, mention any out-of-court declar-ants, or introduce a report prepared by other technicians. Rather, she couched her account of the testing and analysis in generalities and purported to describe her “understanding” of what was done based, largely, on her familiarity with the FBI laboratory’s standard practices. Therefore, the government argues, it introduced no hearsay through Craig, testimonial or otherwise.
We disagree. An out-of-court statement offered in evidence to prove the truth of the matter asserted is hearsay
Appellant argues that Craig similarly incorporated hearsay in her testimony about the random match probability (on which she based her opinion that appellant was the source of the male DNA in Villato-ro’s vaginal swabs and tissue). What Craig reported was the calculation of the RMP as shown in a computer printout generated at her direction by applying the FBI’s PopStats computer program to the DNA profile Craig had received and which she understood to have been obtained from Villatoro and appellant. Craig, however, did not run the program herself; rather, a subordinate allegedly entered the pertinent profile data into the computer, ran the program, and returned to Craig with the printout. The record indicates Craig did not observe her subordinate’s performance of this assignment and therefore had no personal knowledge of what the subordinate did to obtain the printout, or even whether the document was authentic. Of necessity, appellant argues, Craig relied on and implicitly transmitted her employee’s express or implied assertion that he had produced the printout by applying the PopStats program to the relevant DNA profile.
On the other hand, that may not be so. The subordinate’s task may have been purely ministerial or mechanical insofar as his inputting of the data given him by Craig and returning a printout to her may not have involved skilled judgment or analysis or the like. If so, it is at least arguable that the Sixth Amendment did not require his testimony at trial because no assertive conduct on his part was involved. Moreover, it is possible that Craig could infer what procedures were followed from the output itself and the surrounding cir-
The record thus leaves us somewhat uncertain as to whether Craig may have conveyed hearsay in reporting the results of the PopStats calculation, as we do not know exactly what the subordinate did. But in view of our conclusion that Craig relayed critical testimonial hearsay respecting the identity of the DNA profiles about which she testified, we need not resolve the issue with respect to her RMP testimony.
We emphasize, however, that it is too simplistic to say the DNA profiles and the RMP printout were not hearsay because they were “nothing more than raw data produced by a machine.”
This is not a case, moreover, in which out-of-court statements were admitted solely for the non-hearsay purpose of enabling the jury to understand the basis and “evaluate] the reasonableness and correctness” of an expert’s conclusions.
Furthermore, the validity of Craig’s conclusion that appellant was the source of the male DNA found in Villatoro’s vaginal swabs and tissue also depended on Craig’s hearsay testimony stating that the profiles she compared were properly created. Only if the jury credited as true Craig’s testimony that the DNA analysis results— and the associated match probabilities— were correctly generated could it accept her conclusion.
2. Testimonial
The next question is whether the hearsay Craig relayed was testimonial. This court has said in past decisions that “the conclusions of FBI laboratory scientists” who conduct DNA profiling tests are testimonial in nature,
The DNA results obtained at the FBI lab after appellant was identified as a suspect by a cold hit also satisfied the “targeted accusation” criterion set forth in Justice Alito’s plurality opinion in Williams. These “post-targeting” test results included the DNA profile derived from appellant’s buccal sample, the male DNA profile derived from the tissue recovered from Villatoro’s trash can, and the RMP calculation (which, as previously discussed, may or may not have involved hearsay). Each of those results was obtained for “the primary purpose of accusing a targeted individual.”
Thus, Craig conveyed testimonial hearsay under both the basic evidentiary purpose test and the supplemental targeted-accusation requirement. As we explained above, that is enough for purposes of this case to establish a violation of appellant’s Sixth Amendment right of confrontation. In holding otherwise, the trial court deemed it significant that Craig independently analyzed the data produced by the scientists under her supervision and reached her own conclusions. Bullcoming subsequently rejected such a rationale for the admission of testimonial hearsay,
In this case, however, we need not address such possible solutions to the practical difficulties of implementing Crawford in connection with forensic evidence. The government has not argued that practical considerations made it necessary to present its DNA test results through Craig as opposed to witnesses with personal knowledge of the critical testing, and Craig clearly lacked personal and significant involvement in critical parts of the process.
c.
Having found a violation of appellant’s Sixth Amendment right of confrontation, to which he made timely and appropriate objection at trial, we must reverse his conviction unless we can conclude the error was harmless beyond a reasonable doubt.
III. Denial of Discovery
A.
After appellant received the FBI laboratory’s DNA case file in discovery, he requested the government to provide him a report listing all the DNA profiles in the National DNA Index System (“NDIS”) that matched each other at nine or more loci and identifying those that were known to belong to siblings. If the government was unwilling to conduct the “pairwise
Thereafter, approximately one month before the scheduled trial date, appellant moved to compel the government to furnish the discovery he sought on DNA profile matches and near-matches in the NDIS database.
The government opposed appellant’s discovery demand. Disputing the relevance of the requested discovery, the government contended that the partial profile matches found in the state offender databases are neither statistically surprising nor meaningful and that data on pairwise matches in NDIS similarly would cast no doubt on the FBI’s formula for calculating rarity or, in particular, the FBI’s thirteen-loci RMP calculation in this case. Indeed, the government claimed, because the likelihood of a coincidental match at all thirteen tested loci is so minute, scientists have yet to see such a match that did not turn out to involve identical twins. In addition, the government argued, it would take months, if not years, to conduct a full pairwise search of NDIS and obtain the data appellant requested, and appellant’s motion to compel such an effort, filed on “the eve of trial,” was untimely.
B.
Appellant argues that the trial court erred both in finding that the results of an NDIS search would not be material to his defense and in ruling that his motion to compel such a search was untimely. We disagree with appellant on both counts.
1. Materiality
We review a trial court’s determination as to whether information sought by a defendant in discovery would be material to the preparation of his defense for abuse of discretion.
As we have said earlier in this opinion, a RMP statistic calculated by the FBI measures the rarity of a given DNA profile in a particular population; it is a calculation of “the probability of finding a match by randomly selecting one profile from a population of unrelated people.”
To make the required showing that significant flaws in the FBI’s rarity statistics would be shown by searching NDIS for profile matches, appellant relied on the allegedly “astonishing” number of partial matches at nine or more loci found in certain state DNA databases. The primary example of such matches, because it is well-documented and has been studied by researchers, involved Arizona’s offender DNA database. According to a report prepared by the Arizona Department of Public Safety (which appellant submitted
So many matches at nine and ten loci in a collection of only sixty-five thousand profiles may seem “astonishing” when the number is contrasted with microscopically small random match probabilities. For example, the RMP associated with the first nine-loci match found in Arizona’s database reportedly was “1 in 754 million in Caucasians, 1 in 561 billion in African Americans, and 1 in 113 trillion in Southwest Hispanics.”
The foremost explanatory factor is the basic mathematics of the inquiry. As the government pointed out, “when the number of pairwise comparisons in a particular felon database nears the discriminating power of the typing system (which is a function of the number of loci used), partial pairwise matches are expected.” Simply put, a pairwise database search for coincidental matches between each and every DNA profile represented in the database can involve a huge number of comparisons — far more than a database search for a coincidental match with a single DNA profile — and the contrast becomes more and more dramatic as the size of the database increases. In a database containing n entries, the search for a coincidental match with a single DNA profile will require n comparisons; the number grows linearly -with the size of the database. This means that a match is very unlikely if the RMP is tiny, as it typically is when nine or more loci are compared. But the pairwise search of the database for matches requires every profile in the database to be compared with every other, for a total of n(n-l)/2 comparisons. The number of comparisons thus increases as the square of the size of the database. As Professor Kaye says, “[t]his combinatorial explosion ... creates a vastly greater number of opportunities for a match among profiles,” meaning “the database need not be so huge before one can expect many matches that have very small random-match probabilities.”
For each pair, there is only one way to match all thirteen loci, but there are many more ways to get a nine-locus partial match. The profiles in the pair might match at the first nine loci and not match at the next four; they might not match at the first four but then match at the next nine; and so it goes for the (13!)/(9!)(4!) = 715 distinct combinations of nine items out of thirteen. With no particular set of nine loci that need to match, we perform 715 x 2,144,-633,778 comparisons, which gives us more than 1.53 x 1012 opportunities to find some nine-locus matches.[90 ]
In other words, over one-and-a-half trillion nine-loci pairs created from 65,493 profiles were compared in Arizona. Merely to illustrate the potential significance of that calculation, suppose the average RMP for a nine-locus profile in the Arizona database is one in ten billion and that none of the 65,493 profile contributors is related to each other. Then the expected number of nine-locus matches would be (1.53 x 1012) x (10 ~10) = 153 nine-loci matches.
In addition to the sheer size of offender databases and the consequent explosion of combinatorial possibilities for pairwise comparison, the frequency of partial matches in such databases is affected by their makeup. Offender databases are not created from randomized collections of unrelated members of a single defined population; far from it. As the government pointed out, offender databases include DNA profiles of siblings, parents and children, and other close relatives; moreover, they are heterogeneous, meaning they include persons from different population groups in unknown proportions. Each of these factors can lead to more partial matches than one would predict on the basis of random match probabilities alone.
Because close relatives are much more likely than strangers to share the same genes, their DNA profiles have a much greater likelihood of matching than do the
The Arizona data may also indicate how heterogeneity can make a difference. As the government argued, “[i]f members of a Native American tribe in Arizona, who would be expected to share close kinship, commit felonies, their DNA profiles will be added to the state’s offender database,” leading to more partial matches than would otherwise be expected.
Researchers have studied the match frequencies found in offender databases, including the Arizona database, to determine whether they in fact imply that the foundations of the formula for calculating RMPs need to be reconsidered. Appellant and the government presented the trial court with some of their published results. The studies are not conclusive; questions remain. Reputable scientists and scholars have argued that it would be desirable as a matter of policy and scientific accuracy to investigate the frequency of matches in very large databases such as NDIS in order to determine whether the theorized
Furthermore, even if we posit that data from a NDIS search might demonstrate that RMPs as currently calculated could be more accurate, that does not mean the difference would be material in this or any other case. We are not aware that the postulated inaccuracy or error range has been estimated or quantified, but we think it would have to be very substantial indeed to have a material effect on such an extremely low RMP as that calculated in this case (less than one in 2.8 quintillion). What difference could it really make to a jury, for example, if the RMP were increased even a thousand-fold, to one in 2.8 quadrillion? That still would be an extremely low random match probability; and under FBI guidelines, it still would have allowed Rhonda Craig to testify to a reasonable degree of scientific certainty that appellant was the source of the evi-dentiary DNA.
For the foregoing reasons, we conclude that appellant did not meet his burden of showing reason to believe the discovery he sought from the NDIS would enable him to impeach the material accuracy of the FBI’s statistical calculations or otherwise would be material to the preparation of his defense. The trial court did not abuse its discretion in so ruling.
2. Untimeliness
Although our decision with respect to materiality suffices by itself to dispose of appellant’s challenge to the trial
Appellant faults the court for failing to resolve the factual dispute and determine how long the search actually would take. We are not persuaded by that complaint. Presumably, such a determination would have required an evidentiary hearing, which appellant did not request. In any event, we do not think such a hearing would have been required even if appellant had asked for one. The government’s estimate was plausible, and appellant’s counter-argument was weak. As we have explained, a pairwise search of a database requires comparing each profile in the database with every other profile in the database. This takes time. The search of the Arizona database may have taken only half an hour, but that database contained only 65,493 profiles, which meant approximately 2.14 billion pair comparisons. (As previously mentioned, the formula to determine the number of pairwise comparisons in a database containing n profiles is n(n~l)/2.) In contrast, the NDIS contained (at the time the motion for discovery was made in this case) approximately 7.8 million profiles. That translates to over 30.42 trillion pair comparisons — roughly fourteen thousand times the number in the Arizona search.
IV. Conclusion
Although appellant’s discovery claim ultimately fails, he is entitled to relief on his Confrontation Clause claim. Accordingly,
. COD IS is an acronym for the Combined DNA Index System, which is the software used to search and load profiles in the various offender DNA databases maintained on the national, state, and local levels.
. Young had been required to provide a DNA sample for inclusion in the database when he was convicted in 1985 of burglary.
. A ''buccal” sample is obtained by swabbing the cheek area inside of a person's mouth. See United States v. Mitchell, 652 F.3d 387, 406-07 (3d Cir.2011).
. Super. Ct.Crim. R. 16(a).
. To create a DNA profile, the FBI extracts DNA from the sample under examination, amplifies the DNA found, and then examines the genetic code at thirteen specific places, or loci, on the DNA strand. A computer-generated electropherogram displays peaks of varying heights representing alleles at each of these thirteen loci. This "profile” is then compared to the electropherogram from another sample, which may lead to a "match.” See Roberts v. United States, 916 A.2d 922, 926-28 (D.C.2007) (describing analysis process).
. The PopStats program calculates the probability of a random match in several different populations.
. For the sake of clarity, we pause to note that the RMP itself — the probability that a person picked at random would match the crime scene sample — should not be confused with other statistics such as the probability that the suspect was the source of the evidence (and it appears that Craig took care to avoid such confusion in her testimony). "Common erroneous perceptions include the belief that the RMP expresses: the probability that the defendant is the source ('the chance that it’s from him’), the probability that someone other than the defendant is the source (‘the chance that it's not from him'), the probability that the defendant is guilty or not guilty, or the probability that someone else would have the same profile.” David L. Faig-man et al., 4 Modem Scientific Evidence § 31:24, at 184-85 (2012-2013 ed.) (footnotes omitted).
. Craig identified this physical evidence based on the laboratory’s tracking number, the initials of a biologist on her team, and her own examiner symbol, all of which were placed at some point on the packages containing the items. Based on notes prepared by personnel at the lab’s evidence control unit, Craig testified that the packages were still sealed when the lab received them.
. Although the contents of the trash can were submitted to the FBI laboratory in 2006, they were not inspected for some reason until 2010. At that time, lab personnel examined the contents and selected the tissue for DNA testing and typing.
. The government did not rely at Young’s trial on the earlier cold hit match between the vaginal swab profile and Young’s profile in the government database.
. Although she did not run the PopStats program herself, Craig stated that she could tell from the printouts what data had been entered.
. The government has suggested on appeal that Craig’s testimony left open the possibility that she might have observed the DNA testing even though others performed it. We will not indulge that supposition in the evidentiary vacuum before us. The government, as the proponent of Craig’s testimony, had the burden of establishing the basis for its admissibility when appellant objected to it. See, e.g., Patton v. United States, 633 A.2d 800, 810 (D.C.1993) (quoting In re 399 A.2d 556, 558 (D.C.1979)). Yet in responding to appellant’s argument that Craig would be relating testimonial hearsay, the government did not claim that it was not hearsay because
. Crawford v. Washington, 541 U.S. 36, 53-54, 124 S.Ct. 1354, 158 L.Ed.2d 177 (2004).
. Melendez-Diaz v. Massachusetts, 557 U.S. 305, 317, 129 S.Ct. 2527, 174 L.Ed.2d 314 (2009) (internal quotation marks omitted) (holding that the defendant was denied his right of confrontation by the admission at his trial of affidavits reporting drug test results obtained by analysts who did not testify at trial).
. Bullcoming v. New Mexico, 564 U.S. -, 131 S.Ct. 2705, 2715-16, 180 L.Ed.2d 610 (2011) (holding that the introduction of a forensic analyst’s determination of the defendant's blood-alcohol level through the testimony of another analyst who was not involved in the “particular” testing did not comport with the requirements of the Confrontation Clause, even though the surrogate analyst worked at the same laboratory and was qualified to testify as an expert about the lab’s procedures and the process and equipment utilized); Gardner v. United States, 999 A.2d 55, 62 (D.C.2010) (holding that the admission of DNA and serology test results through the testimony of expert witnesses who reviewed and relied on the results but who did not conduct the testing themselves was constitutional error).
.Crawford, 541 U.S. at 51, 124 S.Ct. 1354 (internal quotation marks omitted).
. Davis v. Washington, 547 U.S. 813, 822, 126 S.Ct. 2266, 165 L.Ed.2d 224 (2006).
. Davis, 547 U.S. at 822, 126 S.Ct. 2266 (holding that statements made during 911 call were not testimonial); see also Michigan v. Bryant, 562 U.S. -, 131 S.Ct. 1143, 1166-67, 179 L.Ed.2d 93 (2011) (holding that, under the circumstances, police interrogation of the shooting victim had the primary purpose of responding to the emergency of a roaming gunman and, thus, the elicited statements were not testimonial).
. Bryant, 131 S.Ct. at 1156.
. - U.S. -, 132 S.Ct. 2221, 183 L.Ed.2d 89 (2012).
. Id. at 2229-31 (plurality opinion). There was live testimony at trial, however, from the state analyst who had developed the DNA profile of Williams that was in the database.
. Id. at 2243. The plurality also concluded, in the alternative, that there was no Confrontation Clause problem because the Cellmark report was not offered for its truth, but solely for the non-hearsay purpose of explaining the assumptions underlying the testifying expert's opinion. This was a minority view, however.
. Id.
. Id. (quoting Hammon v. Indiana, 547 U.S. 813, 822, 126 S.Ct. 2266, 165 L.Ed.2d 224 (2006), and Michigan v. Bryant, 562 U.S. -, 131 S.Ct. 1143, 1155, 179 L.Ed.2d 93 (2011)). The Court observed in Bryant that “there may be other circumstances, aside from ongoing emergencies, when a statement is not procured with a primary purpose of creating an out-of-court substitute for trial testimony.” 131 S.Ct. at 1155.
. Williams, 132 S.Ct. at 2244. In Bryant, the Court had reasoned similarly, stating that because the "prospect of fabrication” is lessened when a statement is made to deal with an ongoing emergency rather than to provide evidence, "the Confrontation Clause does not require such statements to be subject to the crucible of cross-examination.” 131 S.Ct. at 1157.
. Id. at 2262 (Thomas, J., concurring in the judgment).
. Id. at 2263.
. Id. at 2261.
. Id. at 2259.
. Id. at 2260 (internal quotation marks omitted). This is subject to Justice Thomas’s caveat that, to curtail prosecutorial abuse, the Confrontation Clause reaches informal statements when they are used "in order to evade confrontation.” Id. at 2260 n. 5 (internal quotation marks omitted). Justice Thomas saw no indication that the Cellmark report had been used for that purpose.
. Id. at 2260.
. Id. at 2274 (Kagan, J., dissenting). Justice Kagan also argued that the DNA analysis performed by Cellmark “to catch a dangerous rapist who was still at large” were not analogous to the statements held in Bryant and Davis to be non-testimonial. Id. (stating that the comparison "stretch[ed] both our ‘ongoing emergency' test and the facts of this case beyond all recognition”).
. Id. at 2276 ("It would not take long to devise the magic words and rules — principally, never call anything a ‘certificate.’ ”).
. Id. at 2265.
. Id. at 2266 (quoting Bullcoming, 131 S.Ct. at 2716).
. Id. at 2264.
. Seminole Tribe of Fla. v. Florida, 517 U.S. 44, 66, 116 S.Ct. 1114, 134 L.Ed.2d 252 (1996); see also Texas v. Brown, 460 U.S. 730, 737, 103 S.Ct. 1535, 75 L.Ed.2d 502 (1983) (a plurality view is "not a binding precedent”); United States v. Pink, 315 U.S. 203, 216, 62 S.Ct. 552, 86 L.Ed. 796 (1942) ("Nor was our affirmance of the judgment in that case by an
. Marks v. United States, 430 U.S. 188, 193, 97 S.Ct. 990, 51 L.Ed.2d 260 (1977) (quoting Gregg v. Georgia, 428 U.S. 153, 169 n. 15, 96 S.Ct. 2909, 49 L.Ed.2d 859 (1976) (opinion of Stewart, Powell, and Stevens, JJ.)).
. King v. Palmer, 950 F.2d 771, 781 (D.C.Cir.1991).
. Id. at 782.
. Thomas v. United States, 978 A.2d 1211, 1225 (D.C.2009).
. Wilson v. United States, 995 A.2d 174, 183 (D.C.2010). For these purposes, a “statement" encompasses not only an oral or written assertion but also nonverbal conduct intended as an assertion. Little v. United States, 613 A.2d 880, 882 (D.C.1992) (adopting the definition of “statement” in Federal Rule of Evidence 801(a)). Implicit assertions are included in the definition as well. See, e.g., Ginyard v. United States, 816 A.2d 21, 40 (D.C.2003).
. Ryan v. Miller, 303 F.3d 231, 248 (2d Cir.2002) (condemning the introduction of a hearsay accusation through testimony stating only that a conversation had taken place and then describing what was done following that conversation); see also United States v. Meises, 645 F.3d 5, 22 (1st Cir.2011) (“[A]ny other conclusion would permit the government to evade the limitations of the Sixth Amendment and the Rules of Evidence by weaving an unavailable declarant's statements into another witness’s testimony by implication.”).
.David H. Kaye, David E. Bernstein, & Jennifer L. Mnookin, The New Wigmore: Expert Evidence § 4.10.2 at 200 (2d ed.2011) [hereinafter The New Wigmore ].
. See Williams, 132 S.Ct. at 2258 (Thomas, X, concurring) ("Lambatos opined that petitioner’s DNA profile matched the male profile derived from LJ.’s vaginal swabs. In reaching that conclusion, Lambatos relied on Cell-mark’s out-of-court statements that the profile it reported was in fact derived from L.J.’s swabs, rather than from some other source.”); id. at 2270 (Kagan, X, dissenting) ("By testifying in that manner, Lambatos became just like the surrogate witness in Bullcoming — a person knowing nothing about ‘the particular test and testing process,’ but vouching for them regardless.”) (quoting Bullcoming, 131 S.Ct. at 2715).
. We see no merit in the government’s argument that appellant failed to object that Craig’s testimony lacked a proper foundation in personal knowledge. On the contrary, that was exactly the point of appellant’s objection that Craig was conveying testimonial hearsay. Cf. Hill v. White, 589 A.2d 918, 922-23 (D.C.1991) (noting that testimony regarding the witness's birth must be hearsay because the witness necessarily lacked personal knowledge about it).
. United States v. Summers, 666 F.3d 192, 202 (4th Cir.2011).
. The New Wigmore § 4.12.5 (2013 Cum. Supp.).
. It is axiomatic, for example, that if a human being does not enter correct information, the output from a computer means nothing. This principle is known in computer science as "garbage in, garbage out” and is traced back to Charles Babbage: "On two occasions I have been asked, — -‘Pray Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?’ ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question.” Charles Babbage, Passages from the Life of a Philosopher 67 (1864).
. Bullcoming, 131 S.Ct. at 2714.
. In re Melton, 597 A.2d 892, 901 (D.C.1991) (en banc) (internal quotation marks omitted) (upholding, inter alia, the admission in civil commitment proceedings of expert psychiatric testimony recounting information obtained by the expert from the patient’s family members and other out-of-court sources, because such information was of a type on which a psychiatrist reasonably would rely in formulating an opinion as to the patient’s future dangerousness); see also Fed.R.Evid. 703.
. See In re Amey, 40 A.3d 902, 912 (D.C.2012) (“Under the common law of the District of Columbia ..., the hearsay bases of an expert witness’s opinions may be presented to the jury on direct examination of the expert, subject to a proper limiting instruction, unless their legitimate probative value in assisting the jury’s assessment of the reasonableness of the opinions is substantially outweighed by their prejudicial effect, i.e. by the risk that, despite the limiting instruction, the jury will consider the hearsay as substantive evidence.”); see also Gardner v. United States, 999 A.2d 55, 60 (D.C.2010) (explaining that Melton "stressed” the necessity of a limiting instruction when otherwise inadmissible hearsay is admitted for the non-hearsay purpose of enabling the jury to evaluate an expert witness’s conclusions).
. In any event, in Williams, five Justices rejected the argument that the Confrontation Clause allows the government to introduce testimonial hearsay for the supposedly “non-hearsay” purpose of explaining the basis of an expert’s opinion. See 132 S.Ct. at 2257-59 (Thomas, J., concurring); id. at 2268-72 (lla-gan, J., dissenting). We agree with them that the non-hearsay rationale for admission does not work because “the purportedly 'limited reason’ for such testimony — to aid the factfin-der in evaluating the expert's opinion — necessarily entails an evaluation of whether the basis is true.” Id. at 2257 n. 1.
[Wjhen a witness, expert or otherwise, repeats an out-of-court statement as the basis for a conclusion, ... the statement's utility is then dependent on its truth. If the statement is true, then the conclusion based on it is probably true; if not, not. So to determine the validity of the witness’s conclusion, the factfinder must assess the truth of the out-of-court statement on which it relies. That is why the principal modern treatise on evidence variously calls the idea that such “basis evidence” comes in not for its truth, but only to help the factfinder evaluate an expert’s opinion "very weak," “factually implausible,” "nonsense,” and "sheer fiction.” ... Admission of the out-of-court statement in this context has no purpose separate from its truth; the factfin-der can do nothing with it except assess its truth and so the credibility of the conclusion it serves to buttress.
Id. at 2268-69 (quoting The New Wigmore § 4.10.1).
. Roberts v. United States, 916 A.2d 922, 938 (D.C.2007).
. Veney v. United States, 936 A.2d 811, 831 (D.C.2007).
. Gardner v. United States, 999 A.2d 55, 58-59 (D.C.2010) ("The government concedes that the conclusions set forth in the DNA and serology reports were ‘testimonial’ .... [and that] the admission of these results, either through the admission of the DNA report or the expert testimony, violated appellant's rights under the Confrontation Clause of the Sixth Amendment because the scientists who actually conducted the testing were not available for cross-examination.”).
. Williams, 132 S.Ct. at 2243 (plurality opinion).
. The critical difference between this case and Williams lies in the fact that the prosecution in this case did not appreciably rely at trial on the cold hit match with a DNA profile in the government database to prove appellant’s guilt, whereas the prosecution in Williams relied exclusively on such a cold hit match.
. Bullcoming v. New Mexico, 564 U.S.-, 131 S.Ct. 2705, 2715-16, 180 L.Ed.2d 610 (2011) ("[Tjhe [Confrontation] Clause does not tolerate dispensing with confrontation simply because the court believes that questioning one witness about another’s testimonial statements provides a fair enough opportunity for cross-examination.”).
. Gardner, 999 A.2d at 61-62 (rejecting admission of DNA evidence based on the theory that the supervising expert had done an "independent analysis” from lab analyst).
. Id. at 62.
. Bullcoming, 131 S.Ct. at 2722 (Sotomayor, J., concurring).
. See Gardner, 999 A.2d at 61; see also The New Wigmore § 4.12.4 at 42 (2013 Cum. Supp.) ("Permitting a supervisor [to testify] is a superficially attractive approach, but it is not supported by careful scrutiny unless, as
.See Williams, 132 S.Ct. at 2244 (Breyer, J., concurring); id. at 2273 n. 4 (Kagan, J., dissenting).
. The New "Wigmore § 4.10.3 at 206.
. Id. § 4.10.2 at 204-05.
. Gardner, 999 A.2d at 58 (citing Chapman v. California, 386 U.S. 18, 24, 87 S.Ct. 824, 17 L.Ed.2d 705 (1967)).
. Id. at 62.
. A “pairwise comparison” involves comparing each profile in the database with every other profile in the database to determine whether they match in whole or in part.
. Appellant filed his discovery motion on March 31, 2010. His counsel had received the DNA case file on December 10, 2009, and asked the government for a report on DNA profile matches in NDIS on or about February 12, 2010. The government had denied that request on February 18, 2010.
. See Super. Ct.Crim. R. 16(a)(l)(C)-(D).
. Appellant explained that the frequency of pairwise matches in the state databases has led some scientists to question the underlying assumptions of the rarity formula — in particular, the assumption that the alleles at the thirteen tested loci are inherited independently of each other, which (if true) permits all their individual probabilities to be multiplied together to determine rarity in accordance with the "product rule.” See United States v. Jenkins, 887 A.2d 1013, 1018 (D.C.2005).
. A "far greater" RMP in appellant’s case would imply a higher (though still low) probability that the DNA profile of Villatoro’s assailant would be the same as Young’s profile if Young were not the source. See The New Wigmore § 14.1.2; David H. Kaye, Trawling DNA Databases for Partial Matches: What is the FBI Afraid Of?, 19 Cornell J.L. & Pub. Pol’y 145, 151 n.27 (2009) [hereinafter Kaye, Trawling DNA Databases ].
. The court was "struck by the uniqueness in this case of what the claim is; ... that there’s a 13-loci match that at least as far as anyone knows ... no one has ever seen outside of the possibility of identical twins.”
. Although we agree that the trial court properly denied appellant's motion as untimely, we deem it desirable to consider the materiality of appellant’s discovery request, both because appellant otherwise could be expected to renew the request on remand before any retrial, and because the same discovery issue has arisen in other cases (including some now pending on appeal).
. United States v. Curtis, 755 A.2d 1011, 1014-15 (D.C.2000) (citing United States v. Lloyd, 992 F.2d 348, 350-51 (D.C.Cir.1993)).
. Id.
. Id. at 1015 (quoting United States v. Mandel, 914 F.2d 1215, 1219 (9th Cir.1990)).
. Id.
. United States v. Jenkins, 887 A.2d 1013, 1018 (D.C.2005). More precisely, ”[t]he random-match probability is the probability that (A) the trace sample would have the identifying features possessed by the individual tested given that (B) the individual tested is not the source.” The New Wigmore § 14.1.2, at 618.
They apply to a hypothetical, infinite population. Obviously the frequency of any observed DNA type ... in a real population on earth cannot be smaller than ... one in seven billion or so. The large exponents in the powers of 10 [in more miniscule RMPs] mean that the features that constitute the full DNA profile ... are extremely variable — there are so many possible, complex types that only a small fraction of them will be realized in an actual population.
Id. § 14.1, at 611.
. “The product rule provides that ‘if two events are independent of each other, the probabilities of each occurring can be multiplied, and the resulting product is the probability of both events occurring.' " Jenkins, 887 A.2d at 1018 n. 6 (quoting State v. Link, 25 S.W.3d 136, 144 (Mo.2000)).
. See Jenkins, 887 A.2d at 1018. At trial, Craig was asked about the theta (mistran-scribed as "stata”) correction. She stated that it “is a measure of the amount of nonrandom mating that could exist in population groups.... It is sort of a correction for that amount.... It's applied when there's what we consider a [homozygotic] profile," which is when someone has a matching set of alleles at a particular locus, because then parents could "happen to be related.” The value of the correction is .01. See also United States v. Morrow, 374 F.Supp.2d 51, 58-60 & n. 8 (D.D.C.2005) (explaining calculation of allelic frequencies and use of the "theta inbreeding coefficient correction”).
. See Jenkins, 887 A.2d at 1018; Morrow, 374 F.Supp.2d at 59-60.
. See, e.g., Bruce S. Weir, Matching and Partially-Matching DNA Profiles, 49 J. Forensic Sci. 1009 (2004) (finding that observed numbers of pairs of individuals with various numbers of matching or partially matching loci in CODIS data published by the FBI and in forensic database data reported by Australian authorities are in "good overall agreement” with numbers predicted by application of the product rule with the theta correction; "getting é = 0.01 does produce a conservative result at nearly every locus in all three samples").
. See, e.g., Yun S. Song et al., Average Probability That a “Cold Hit” in a DNA Database Search Results in an Erroneous Attribution, 54 J. Forensic Sci. 22, 23 (2009) (noting that "there is a consensus about using the recommendation of NRC II for computing the RMP”); id. at 24 (recognizing "a consensus that the theta correction using the recommended values of theta provides a conservative basis for computing the per-locus match probabilities”) [hereinafter Song, Average Probability ].
. One pair of profiles matched at eleven loci and one pair matched at twelve loci, but these matches were between confirmed siblings. The extent to which relatives were involved in the nine-loci and ten-loci matches was not determined.
. See People v. Wright, 361 Ill.Dec. 447, 971 N.E.2d 549, 561-62, 567 (Ill.App.Ct.2012) (relating findings of 903 matches at nine or more loci in Illinois' 220,000-profile database and 32 such matches in Mainland's under-30,000-profile database).
. Erin Murphy, The New Forensics: Criminal Justice, False Certainty, and the Second Generation of Scientific Evidence, 95 Cal. L.Rev. 721, 782 (2007).
. Kaye, Trawling DNA Databases, at 156. To understand this point, it may be helpful to appreciate that the phenomenon
*1054 is analogous to the famous “birthday problem.” The problem is to determine the minimum number of people in a room such that the odds favor there being at least two of them who were born on the same day of the same month. In its simplest form, the birthday problem assumes that equal numbers of people are born every day of the year. Since the random-match probability for a specified birthday is about 1/365, most people think that more than 180-some people must be in the room. Indeed, one might think that for a match to be likely, the number should be larger still. After all, the chance of a match between two randomly selected individuals having a given birthday (say, January 1) is a miniscule 1/365 x 1/365 = 1/133,225.
But a precise calculation shows that it takes only 23 people before it is more likely than not that at least two people in the room share a birthday. The actual number is this small because the matching birthday can be any one of the 365 days in the year and because the number of comparisons among birthdays scales as re2 with an increasing number n of people in the room.
Id. at 156-57 (footnotes omitted). See also Bruce S. Weir, The Rarity of DNA Profiles, 1 Annals Applied Stat. 358 (2007).
. Kaye, Trawling DNA Databases, at 157 (footnotes omitted). A similar calculation can be performed with respect to the number of 10-loci comparisons: there are (13!)/(100(3!) = 286 ways of obtaining a ten-loci match, resulting in 286 x 2,144,633,778 = 6.13 x 1011 (613 billion) different pairings.
. See id. Although we do not know the average RMP that would be applicable to the Arizona database, it appears that a one-in-ten-billion RMP for a nine-loci profile is not atypical. See Guangyun Sun et al., Global Genetic Variation at Nine Short Tandem Repeat Loci and Implications on Forensic Genetics, 11 Eur. J. Hum. Genetics 39, 45 (2003).
. Kaye, Trawling DNA Databases, at 170 & n.143 (citing Allen Beck et al., Bureau Just. Stat., Survey of State Prison Inmates 9 (1991) (37% of inmates reported having a parent or sibling "who had served time”); Doris L. James, Bureau Just. Stat., Profile of Jail Inmates 9 (2002) (national survey of jail inmates found that 46% of the inmates had a sibling or parent who had been incarcerated)).
. See, e.g., Bruce Budowle, F. Samuel Baechtel, & Ranajit Chakraborty, Partial Matches in Heterogeneous Offender Databases Do Not Call into Question the Validity of Random Match Probability Calculations, 123 Int’l J. Legal Med. 59, 60 (2009) (explaining that "the number of matched loci becomes highly distorted toward the direction of a larger number of matched loci in the presence of relatives in the database, and the deviation depends on the extent of the number of relatives as well'').
. In a 2008 study. Professor Laurence Mueller estimated the number of sibling profiles that needed to be present in the Arizona database to explain the observed partial match results at nine and ten loci under the standard assumption of allelic independence relied on to compute random match probabilities. Mueller concluded that there had to be roughly one to three thousand sibling pairs, meaning between 3.1% and 9.2% of the profiled offenders had to have siblings in the database. Mueller also concluded that "[m]ore remote relatives, even as close as parents and offspring, are unlikely to help much at explaining these observations.” See Laurence D. Mueller, Can Simple Population Genetic Models Reconcile Partial Match Frequencies Observed in Large Forensic Databases?, 87 J. Genetics 101, 107 (2008). The actual makeup of the Arizona database is not known, but if Kaye is correct about the likely prevalence of close relatives in offender databases, Mueller’s estimate appears plausible.
.Another factor to bear in mind is that duplicate DNA profiles appear in offender databases because offenders use aliases and because different jurisdictions collect and submit DNA profiles of the same offender. Undetected duplications artificially inflate the number of full matches in a database.
. See, e.g., Song, Average Probability, at 24 ("[F]ailure to reject the hypothesis of independence across loci is not equivalent to verifying that the RMP computed from the product rule is accurate. Only by carrying out more studies [of profile matches in databases] can we be sure that multiplying across loci produces accurate results....”); Kaye, Trawling DNA Databases, at 170 (urging the government to. make an “anonymized version of NDIS” available to researchers because, while "[s]tudies to date tend to support the accepted method for computing random-match probabilities, ... these studies are limited by sample size and the lack of details on individual profiles and familial relationships of the individuals whose DNA profiles are in the databases”).
. See Kaye, Trawling DNA Databases, at 149. The DNA Identification Act of 1994, 42 U.S.C. §§ 14131-14136e (2006), also restricts access to the NDIS database.
. Kaye, Trawling DNA Databases, at 164; see also id. at 161-62 ("The studies of the few numbers reported in Arizona do not demonstrate that the theoretical computations [of RMPs] yield absurdly small estimates of the true probabilities of a match among unrelated individuals.”).
. We express no view on the appropriateness vel non of an expert opinion so framed.
. When the trial court asked defense counsel during the argument on his discovery motion whether there was “any projection from anyone” as to how the NDIS search results might affect the RMP, counsel admitted there was not.
. See United States v. Curtis, 755 A.2d 1011, 1016 (D.C.2000).
. And that initial search, the government argued, would only be the beginning. The process of identifying duplicate and sibling profiles would itself be a "massive undertaking,” the government explained, because
[T]he FBI only has access to the personally identifiable information relating to federally convicted offenders at NDIS. The remainder of the convicted offender records do not contain personally identifiable information sufficient to ascertain duplicate or sibling profiles and it would not be possible to identify any such duplicate or sibling profiles at the National level. To ascertain such information would require extensive research by each and every state and local law enforcement agency which would, in turn, have to be checked against each and every state and local database because felons can be registered in any number of different local and state databases, along with the federal database. There is simply no way to estimate how many months/years it would take the states and local authorities to comply with such a request.
.A back-of-the-envelope estimate indicates that a NDIS pairwise comparison done at Arizona speeds therefore would take roughly 10 months (if the computer ran non-stop).