United States v. Porter

618 A.2d 629, 1992 D.C. App. LEXIS 323, 1992 WL 381836

• Court: District of Columbia Court of Appeals
• Decided: December 22, 1992
• Docket: 91-CO-1277
• Status: Published

Opinions

SCHWELB, Associate Judge:

This appeal presents our court for the first time with the question whether “DNA” profiling evidence is admissible to corroborate the identification of a defendant in a criminal case. Provided that, as we anticipate, certain limited questions are successfully resolved on remand, the proponents of a technology which we view as a potentially valuable tool in the search for the truth carry the day.

I

THE PACTS

A grand jury indicted Kevin E. Porter on February 28, 1990, on one count of rape, D.C.Code § 22-2801 (1989), and one count of carnal knowledge. Id. The indictment was precipitated by Porter’s alleged sexual assault upon the fourteen year-old sister of his girlfriend. Before trial, the prosecution filed a motion requesting the court for leave to introduce expert testimony that the deoxyribonucleic acid (DNA) extracted from semen specimens taken from the crime scene matched the DNA taken from Porter's blood. The government also sought to introduce evidence that the probability of a coincidental DNA match between two unrelated black males was no higher than one in thirty million.¹ The DNA evidence was thus intended to corroborate the complainant’s expected identification of Porter as her assailant and to demonstrate that it was extremely improbable that someone other than Porter had committed the crime.

In response, Porter asked the court to exclude the proffered DNA identification evidence. He argued that the technology that the FBI had used to determine that his own DNA matched the DNA taken from the semen samples was lacking in quality control assurance and had not been generally accepted in the relevant scientific community. Porter also contended that the methodologies used by the FBI to calculate “coincidental match probabilities” likewise lacked general scientific acceptance. As a result, Porter argued, the government’s proffered DNA evidence failed to meet the standard for the admissibility of novel scientific techniques set forth in the landmark case of Frye v. United States, 54 App.D.C. 46, 293 F. 1013 (1923).

Porter’s case was consolidated with eleven other prosecutions in which the admissibility of DNA evidence was at issue. During the twenty-day Frye hearing which followed, the judge heard testimony from eight expert witnesses, admitted over 110 exhibits, and received over 1,300 pages of briefs. The judge later issued an order, accompanied by a 93-page opinion, in which he held that the proffered DNA identification evidence was inadmissible. United States v. Porter, 120 Daily Wash. L.Rptr. 477 (Super.Ct.D.C.1991). The judge concluded that the FBI’s method for determining that a defendant’s DNA matched DNA taken from the crime scene was based on procedures generally accepted in the scientific community as reliable. He ruled, however, that the FBI’s procedure for calculating coincidental match probabilities, and for arriving at the figure of one in thirty million, were not based on generally accepted techniques, and that the proffered evidence was therefore inadmissible under Frye. The judge observed that a number of studies were pending on the subject of the forensic use of DNA evidence and were expected to address issues with respect to which, as of the time of writing, there was scientific disagreement. He stated that “[i]t is after these studies and others, such as the study which is being prepared by the National Academy of Sciences [NAS] have been completed, when the court should be called upon to admit DNA evidence, not before.” (Emphasis in original). Id. at 507.

In the Porter case only, the government filed a pretrial appeal pursuant to D.C.Code § 23-104(a)(l) (1989). During the pendency of the appeal, the National Research Council of the NAS issued the comprehensive and long-awaited report dealing with forensic DNA methodologies to which the judge alluded in his opinion. See Committee on DNA Technology in FoRensic Science, NaTIONAL RESEARCH COUNCIL, DNA TECHNOLOGY in FoREnsic Science (1992) [hereinafter NRC Report]. In response to the NRC Report, the parties and the Public Defender Service, as amicus curiae, filed supplemental submissions to their already imposing briefs.²

We hold, essentially for the reasons stated by the trial judge, that the FBI’s procedures for determining a match pass muster under Frye. We also agree with the judge that there was no consensus within the relevant scientific community in support of the FBI’s calculation that the probability of a coincidental match was no higher than one in thirty million (or, a fortiori, one in forty million). We specifically decline the government’s invitation to hold that the position of one group of distinguished scientists (those favoring the government’s position) is more persuasive, as a matter of molecular biology or population genetics, than the position of an apparently equally distinguished group of scholars who have reached an opposite conclusion; indeed, we view the government’s position on this issue as contrary to Frye. We thus agree with the trial judge’s resolution of the principal issues which he addressed.

Nevertheless, we remand the case to the trial court. We do so for two reasons. First, at least in our view, the NRC Report, which was not available to the trial judge, suggests that the DNA evidence should be admitted on the basis of a probability calculation for which the requisite consensus may now exist. Second, we think it important to clarify a point on which the parties have not significantly focused, but which may considerably simplify the issue before the court.

We hold that it is not necessary for the prosecution to prove, in order that DNA evidence be admitted, that there is a scientific consensus as to the precise probability of a coincidental match. So long as there is a consensus that the chances of such a match are no greater than some very small³ fraction, then the evidence is probative and should be admitted on an appropriately conservative basis. If, as the information available to us now suggests, reputable scientists would agree on some such minimal figure as the bottom limit of the possibility of a coincidental match, the evidence will be admissible under the Frye standard. On remand, however, Porter must have the opportunity to contest, if he can, the sufficiency of the government’s showing that the relevant scientific consensus, as defined in this opinion, now exists.

II

ALLELES, CHROMOSOMES, AND POLYMORPHISMS — THE NATURE OF DNA IDENTIFICATION EVIDENCE⁴

“The techniques of DNA typing are fruits of the revolution in molecular biology that is yielding an explosion of information about human genetics.” NRC Report, supra, at 2. The opinion of the trial court contains a detailed exposition of the technology on which the prosecution relies in this case. Porter, 120 Daily Wash.L.Rptr. at 483-85; see also United States v. Jakobetz, 955 F.2d 786, 791-93 (2d Cir.1992), cert. denied, - U.S. -, 113 S.Ct. 104, 121 L.Ed.2d 63 (1992). We attempt our own brief summary, in lay terms, of an esoteric but fascinating subject.

DNA is sometimes called the blueprint of life. It contains the chemical instructions for all of life’s processes, as well as the “genetic code” that defines who we are, what we look like, and where our talents lie. With the exception of identical twins, no two people have the same DNA. The makeup of one’s DNA remains constant throughout one’s life. In recent years, forensic technologies have been developed for removing the DNA from human cells discovered at crime scenes and for comparing the evidentiary sample with the suspect’s DNA. We must determine whether these technologies pass muster under Frye.

Embedded within the nucleus of virtually every cell of each human being’s body are forty-six rod-shaped chromosomes. Half of these chromosomes are inherited from one’s mother and half are inherited from one’s father. Each chromosome has the shape of a twisted ladder or spiral staircase. The “banisters” of this staircase are made of phosphates and sugars, while the “steps” or “rungs” consist of “base pairs,” or pairs of amino acids bound together. A single DNA molecule — itself not a very large entity — contains about three billion base pairs.

Located at specific sites, or “loci,” along each chromosome are large groups of base pairs known as “alleles,” or “genes.” Over 99% of these genes are identical among all human beings. These genes define us as persons, rather than animals, plants, or other forms of life. They account for the many shared characteristics of all human beings. The remaining genes — known as “polymorphic” genes because they vary in form from person to person — account for our unique characteristics as individuals. Many polymorphic genes are known to have definite functions: some are responsible for the color of our hair and of our eyes, some for the shape of our body and the type of our blood. Other polymorphic genes, however, appear to have no function whatever. These “junk DNA” segments, which typically consist of varying lengths of repeating sequences of base pairs, form the basis for the DNA identification evidence at issue in this case.

The remarkable technology which has provided molecular biologists with an entree into the wonders of sub-microscopic exploration has not yet enabled them to compare every base pair in one DNA molecule with every base pair in another to determine conclusively that the two molecules are, in fact, identical. Forensic scientists, seeking to apply the new technology to identify the guilty and to vindicate the innocent, have developed a “shortcut” for making this determination. After extracting and “cutting” DNA from cells taken from the crime scene and from cells taken from the defendant, they isolate, from each sample, maternal and paternal fragments of “junk DNA” from four different loci, and measure the length of the repeating sequence in each fragment. In other words, rather than comparing every base pair in the two DNA molecules, they compare eight of the defendant’s genes against the genes in the same locations on the evidentiary sample DNA to see if they are consistent with each other. This process is known as “restriction fragment length polymorphism,” or, more manageably, as RFLP. It is aimed at measuring the “variable number of tandem repeats,” a concept which DNA aficionados rattle off as VNTR.

Because each person has thousands of polymorphic genes, it is theoretically possible for two people to have identical genes in these four locations on their DNA molecules but to have differences — perhaps even hundreds of differences — in other locations. Accordingly, once it has been determined that the defendant’s DNA and the DNA from the evidentiary sample share identical patterns at all four of the locations examined, scientists calculate the possibility that the match is merely a coincidence and that the two samples did not actually come from the same person.

Making that calculation is generally the role of human population geneticists. The particular system followed by the FBI and presented by the prosecution to the trial court is known as “fixed bin analysis.” Scientists utilizing this process first estimate, for each of the loci which was analyzed on the defendant’s DNA, the fraction of people in the defendant’s broad racial or ethnic group, e.g., Caucasian, Black American, or Hispanic, with genes at that locus identical to the defendant’s genes. They then perform a series of multiplications to determine the fraction of the defendant’s group with identical DNA fragments at all four of the loci examined. The resulting fraction is generally an astronomically low one.⁵

Ill

LEGAL DISCUSSION

A. The Frye Test.

In this jurisdiction, the starting point of our legal inquiry must be the test enunciated in Frye:

Just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. Somewhere in this twilight zone the evidential force of the principle must be recognized, and while courts will go a long way in admitting expert testimony deduced from a well-recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs.

54 App.D.C. at 47, 293 F. at 1014. Although it is now forty years since James Watson of the United States and Francis Crick of Great Britain received the Nobel Prize for their pioneering work on the DNA molecule, see People v. Axell, 235 Cal.App.3d 836, 845, 1 Cal.Rptr.2d 411, 415 (1991), review denied, (1992), forensic use of DNA technologies is of comparatively recent vintage (but boundless potential). See People v. Wesley, 140 Misc.2d 306, 307-11, 533 N.Y.S.2d 643, 644-46 (1988), (Wesley I), aff'd 183 A.D.2d 75, 589 N.Y.S.2d 197 (3d Dept.1992) (Wesley II). The use of DNA evidence in criminal cases is at the “cutting edge” of forensic science. Wesley I, supra, 140 Misc.2d at 307, 533 N.Y.S.2d at 644. This appeal therefore presents the very kind of issue which the quoted language from Frye was designed to address.

As Judge McGowan explained for the court in United States v. Addison, 162 U.S.App.D.C. 199, 201, 498 F.2d 741, 743 (1974),

the Frye standard retards somewhat the admission of proof based on new methods of scientific investigation by requiring that they attain sufficient currency and status to gain the general acceptance of the relevant scientific community.

Some jurisdictions have therefore abandoned Frye for a more liberal approach. See, e.g. Jakobetz, supra, 955 F.2d at 794. This court, however, continues to adhere to the traditional standard. Street v. Hedgepath, 607 A.2d 1238, 1244 (D.C.1992); Jones v. United States, 548 A.2d 35, 39-40 (D.C.1988); Ibn-Tamas v. United States, 407 A.2d 626, 637-39 (D.C.1979).

We agree with the government that, under Frye, the proponent of a new technology must demonstrate by a preponderance of the evidence that this technology has been generally accepted in the relevant scientific community. Yee, supra, note 4, 134 F.R.D. at 195-96; see also Jakobetz, supra, 955 F.2d at 796 (declining in DNA case, to require proof of reliability beyond a reasonable doubt); United States v. Roy, 114 Daily Wash.L.Rptr. 2481, 2489 (Super.Ct.D.C.1986);⁶ cf. Kelly v. State, 824 5.W.2d 568, 573 (Tex.Cr.App.1992) (requiring proof of reliability in DNA case to be by clear and convincing evidence; Texas is a non -Frye jurisdiction, however, and general acceptance need not be demonstrated).

Given the requirement in Frye of “general acceptance,” "[t]he issue is consensus versus controversy over a particular technique, not its validity.” Jones, supra, 548 A.2d at 42 (citation omitted). As we bluntly put it in Jones, the prime focus is “on counting scientists’ votes, rather than [on] verifying the soundness of a scientific conclusion.” Id.; but cf. People v. Mohit, 153 Misc.2d 22, 579 N.Y.S.2d 990, 992 (West-chester County Ct.1992) (counting heads rarely feasible and can be of dubious value). Courts recognize that some “scientists” will testify to almost anything,⁷ and unanimity is not required. People v. Middleton, 54 N.Y.2d 42, 49, 429 N.E.2d 100, 103, 444 N.Y.S.2d 581, 584 (1981); cf. Yee, supra, 134 F.R.D. at 166, 197, 202. Nevertheless, general acceptance is general acceptance. If “scientists significant either in number or expertise publicly oppose [a new technique] as unreliable,” then that technique does not pass muster under Frye. People v. Shirley, 31 Cal.3d 18, 56, 181 Cal.Rptr. 243, 266, 723 P.2d 1354, 1377 (1982) (en banc).

The consensus that will satisfy Frye “is that of scientists, not courts,” People v. Reilly, 196 Cal.App.3d 1127, 1135, 242 Cal.Rptr. 496, 500 (1987), for “[a] courtroom is not a research laboratory.” United States v. Brown, 557 F.2d 541, 556 (6th Cir.1977). Accordingly, “the court may not resolve a scientific dispute between opponents and proponents of the technique, [and] the very existence of the dispute precludes admission of the testimony.” Starr v. Campos, 134 Ariz. 254, 257, 655 P.2d 794, 797 (1982); cf. Friend v. Friend, 609 A.2d 1137, 1139-40 (D.C.1992) (distinguishing the existence of dispute from the merits of that dispute).

We have stated that the Frye test “begins — and ends — with ... whether there is general acceptance of a particular scientific methodology, not an acceptance, beyond that, of particular study results based on that methodology.” Ibn-Tamas, supra, 407 A.2d at 638. The trial judge held, and we agree, that under the Ibn-Tamas articulation, “what must be generally accepted is forensic DNA analysis and not ... beyond that ... the results of that analysis in a particular case.” Porter, 120 Daily Wash.L.Rptr. at 494.⁸

The trial judge also rejected the prosecution’s tentative (and somewhat astonishing) proposal that he severely restrict the categories of scientists whose views he should consider in assessing general acceptance:

It simply is not creditable to argue, and the government does not do so with much enthusiasm, that general acceptance may be premised simply on the opinion of forensic scientists. Were it otherwise, there would have been no need for a month-long Frye hearing. There is no question but that forensic scientists accept — no qualifier is necessary — forensic DNA evidence and believe that the time has come for its use as powerful evidence in criminal trials. While views of forensic scientists have weight and must be considered, “members of the relevant scientific field will include those whose scientific background and training are sufficient to allow them to comprehend and understand the process and form a judgment about it.” Reed v. State, 283 Md. 374, 391 A.2d 364, 368 (1978). This court holds that this formulation states the relevant scientific field.

Porter, 120 Daily Wash.L.Rptr. at 495 (footnote omitted). We agree with the judge. See also Axell, supra, 235 Cal.App.3d at 857, 1 Cal.Rptr.2d at 424 (“[sjince DNA profiling is an amalgamation of primarily two disciplines, molecular biology and population genetics ..., it appears logical to consider its acceptance by those communities for forensic use.”)

B. The Scope of Review.

Generally, the decision whether or not to admit expert testimony is addressed to the sound discretion of the trial court. Street, supra, 607 A.2d at 1244; Jones, supra, 548 A.2d at 38. Where the question of the general acceptance of a new scientific technique is raised, however, the proponent will often be asking the court to establish the law of the jurisdiction for future cases. Jones, supra, 548 A.2d at 40. This is certainly true in the present instance. Accordingly, in recognition of the fact that the formulation of the law of this jurisdiction is a quintessentially appellate function, see Griffin v. United States, 618 A.2d 114, 117-119 (D.C. Dec. 18, 1992), we engage in a broad review of the trial judge’s determination whether the forensic use of DNA technology has gained general acceptance. Jones, supra, 548 A.2d at 40. In doing so, we may consider not only expert evidence of record, but also judicial opinions in other jurisdictions, as well as pertinent legal and scientific commentaries. Id. at 41. The amount of reading which the parties and amicus have invited us to undertake has therefore been challenging to say the least.

C. Determining a Match.

During the Frye hearing, Porter subjected the FBI’s RFLP procedure for determining a match between his own DNA and the evidentiary sample to a “blunderbuss” attack⁹ from a number of different directions.¹⁰ He reargues most or all of his contentions in this court, often in colorful if not altogether understated rhetoric.¹¹

The trial judge addressed each of Porter’s contentions in considerable detail. He concluded that the method of DNA typing used by the FBI forensic laboratory was generally accepted in the scientific community. Porter, 120 Daily Wash.L.Rptr. at 503. He found some of the defense objections to the FBI’s procedures to be overstated, some irrelevant, and some unsupported by scientific evidence. Id.

The recent NRC Report has generally reinforced the judge’s views. See Bridgett, supra, 120 Daily Wash.L.Rptr. at 1703-04. Neither Porter, nor the Public Defender Service as amicus curiae, has brought to our attention any judicial decision holding or even implying that the FBI’s technology for determining a match (as distinguished from its methodology for calculating the probability of a coincidental match) lacks general acceptance in the relevant scientific community.¹² The case law overwhelmingly supports the trial judge’s conclusion that the “match” technology is generally accepted. See State v. Vandebogart, — N.H. —, -, 616 A.2d 483, 491-93 (1992); State v. Davis, 814 S.W.2d 593, 602 (Mo.1991); Axell, supra, 235 Cal.App.3d at 856 & n. 7, 1 Cal.Rptr.2d at 422-23 & n. 7; Wesley II, supra, 183 App.Div.2d at 77-79, 589 N.Y.S.2d at 199-201; Bridgett, supra, 120 Daily Wash.L.Rptr. at 1703-04, all citing numerous precedents.

For the reasons stated by the trial judge in this case and by the courts in the opinions cited above, we are satisfied that, provided the FBI’s methodology is properly carried out, the possibility of a false positive match is negligible. “Even if [an erroneous match] were theoretically possible ... the statistical likelihood of an artificial match at all eight bands is extraordinarily low.” Axell, supra, 235 Cal.App.3d at 860, 1 Cal.Rptr.2d at 426. “Clinical errors are far more likely to cause an inconclusive or no match result than a false positive.” Mohit, supra, 579 N.Y.S.2d at 995. Any failure by the scientists to adhere to the appropriate procedure is, of course, a proper subject of inquiry, but does not raise an issue which implicates Frye.

D. The Prosecution’s Statistical Calculations and the Controversy Among Scientists.

In the trial court, the prosecution elected to put all of its eggs in a single basket. It contended below, and maintains on appeal, that there was general aecep-tance in the relevant scientific community, within the meaning of Frye, of the statistical methodology by which the possibility of a random match was calculated as being one in thirty million. The trial judge rejected this contention, noting the existence of a substantial controversy among distinguished scientists as to the soundness of certain assumptions on which this calculation was predicated. Porter, 120 Daily Wash.L.Rptr. at 505-06. We agree with the trial judge’s analysis, which has been further reinforced by subsequent events.

In the very recent case of People v. Barney, et al., 8 Cal.App. 4th 798, 10 Cal.Rptr.2d 731 (1st Dist.1992), the California prosecutor presented essentially the same arguments as the government is making here. The court was not persuaded. We quote at length from Judge Chin’s lucid analysis for the unanimous court in Barney:

There is currently a fundamental disagreement among population geneticists concerning the determination of the statistical significance of a match of DNA patterns. The dispute was recently featured in a leading scientific journal, Science, in which Richard C. Lewontin of Harvard University and Daniel L. Hartl of Washington University attack the reliability of DNA statistical analysis, while Ranajit Chakraborty of the University of Texas and Kenneth K. Kidd of Yale University defend it. (Lewontin & Hartl, Population Genetics in Forensic DNA Typing (Dec. 20,1991) Science, at p. 1745 (hereafter Lewontin & Hartl) Chakraborty & Kidd, The Utility of DNA Typing in Forensic Work (Dec. 20, 1991), Science, at p. 1735 (hereafter Chakraborty & Kidd)).

Lewontin and Hartl question the reliability of the current method of multiplying together the frequencies with which each band representative of a DNA fragment appears in a broad data base. The problem, they say, is that this method is based on incorrect assumptions that (1) members of the racial groups represented by the broad data bases — Caucasians, Blacks, and Hispanics — mate within their groups at random, i.e., without regard to religion, ethnicity, and geography, and (2) the DNA fragments identified by DNA processing behave independently and thus are “independent in a statistical sense” — i.e., in the language of population genetics, they are in ‘linkage equilibrium.’ (Lewontin & Hartl, supra, at p. 1746.)

Lewontin and Hartl claim that, contrary to the assumption of random mating, ethnic subgroups within each data base tend to mate endogamously (i.e., within a specific subgroup) with persons of like religions or ethnicity or who live within close geographical distance. Such endogamous mating tends to maintain genetic differences between subgroups— or substructuring — which existed when ancestral populations emigrated to the United States and has not yet had sufficient time to dissipate. As a result, the subgroups may have substantial differences in the frequency of a given DNA fragment — or VNTR allele — identified in the processing step of DNA analysis. A given VNTR allele may be relatively common in some subgroups but not in the broader data base. (Lewontin & Hartl, supra, at pp. 1747-1749.)

* * * * * *

Lewontin and Hartl conclude that because the frequency of a given VNTR allele may differ among subgroups, reference to a broad data base may produce an inaccurate frequency estimate for a defendant's subgroup. The current multiplication method may greatly magnify the error. The resulting probability for the defendant’s entire DNA pattern may be in error by two or more orders of magnitude (e.g., 1 in 7.8 million could really be ' 1 in 78,000). (Lewontin & Hartl, supra, at p. 1749.)

Chakraborty and Kidd strongly disagree. They contend that Lewontin and Hartl exaggerate both the extent of en-dogamy in contemporary America and the effect of substructuring on the reliability of DNA statistical analysis. They concede there is substructuring (and thus variance of VNTR allele frequencies) within the data bases but assert its effect on the reliability of frequency estimates is “trivial”, and “cannot be detected in practice.” (Chakraborty & Kidd, supra, at pp. 1736-1738.)

In an article introducing the Lewontin-Hartl and Chakroborty-Kidd articles, Science describes Lewontin and Hartl as “two of the leading lights of population genetics” who “have the support of numerous colleagues.” (Roberts, Fight Erupts Over DNA Fingerprinting (Dec. 20, 1991) (Science, at p. 1721 (hereafter Fight Erupts)). A population geneticist at the University of California at Irvine is said to agree “that the current statistical methods could result in ‘tremendous’ errors and should not be used without more empirical data.” (Id. at p. 1723.) The introductory article describes the debate as “bitter” and “raging,” stating that “tempers are flaring, charges and countercharges are flying_ [] Dispassionate observers, who are few and far between, say that the technical arguments on both sides have merit.... [T]he debate is not about right and wrong but about different standards of proof, with the purists on one side demanding scientific accuracy and the technologists on the other saying approximations are good enough.” (Id., at p. 1721.) Science concludes that the Lewontin-Hartl and Chakroborty-Kidd articles “seem likely to reinforce the notion that the [scientific] community is indeed divided” under the Frye standard, although the issue may become moot within a few years “with the expected introduction of even more powerful DNA tech-niques_” (Id. at p. 1723.)

The NRC report, which was released four months after the Science articles, acknowledges there is a “[s]ubstantial controversy” concerning the present method of statistical analysis. (NRC rep., supra, at p. 74.) The report does not, however, choose sides in the debate, but instead “assume[s] for the sake of discussion that population substructure may exist_” (NRC rep., supra, at pp. 12, 80; see also id. at p. 94.)

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Evidently, Lewontin and Hartl — along with their colleagues who agree with them, — are significant in both ‘number’ and ‘expertise.’ [Citation omitted.] Science describes Lewontin and Hartl as “two of the leading lights of population genetics” who “have the support of numerous colleagues,” and quotes a third population geneticist (Francisco Ayala) who agrees with the above criticism. (Fight Erupts, supra, at p. 1721.) Le-wontin has been described by one of his colleagues as ‘probably regarded as the most important intellectual force in population genetics alive.’ (U.S. v. Yee (N.D.Ohio 1991) 134 F.R.D. 161, 181.) Similar criticism of the statistical calculation process of DNA analysis have been leveled by other scientists in previous publications, some of which were admitted in evidence below (e.g., Lander, DNA Fingerprinting on Trial (June 15, 1989) Nature, at pp. 501, 504; Cohen, DNA Fingerprinting for Forensic Identification: Potential Effects on Data Interpretation of Subpopulation Heterogeneity and Band Number Variability (1990) 45 Am.J.Hum.Genetics 358, 367).

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[T]he point is not whether there are more supporters than detractors,[¹³] or whether (as the Attorney General and amicus curiae claim) the supporters are right and the detractors are wrong[¹⁴] The point is that there is disagreement between two groups, each significant in both number and expertise (a “[substantial controversy,” in the words of the NRC report). (NRC rep., supra, at p. 74.) Even Science, which purportedly sought balance in its coverage of this dispute by commissioning the Chakraborty-Kidd article as a rebuttal to the Lewontin-Hartl article (Roberts, Was Science Fair to its Authors? (Dec. 20, 1991) Science, at p. 1722, recognized that the competing articles “seem likely to reinforce the notion that the [scientific] community is indeed divided” under the Frye standard. {Fight Erupts, supra, at p. 1723.)

Our task under Kelly[15]-Frye is not to choose sides in this dispute over the reliability of the statistical calculation process. Once we discern a lack of general scientific acceptance — which in this instance is palpable — we have no choice but to exclude the “bottom line” expression of statistical significance in its current form.

Barney, supra, 8 Cal.App. 4th at 814-19, 10 Cal.Rptr.2d at 740-43; accord, Pizarro, supra n. 12, 10 Cal.App. 4th at 78-90, 12 Cal.Rptr.2d at 451-58.

The decisions in Barney and Pizarro are no aberrations. Although it is true, as the government contends, that the decisions admitting DNA match probabilities outnumber those reaching a contrary result, the imbalance is not as great (and certainly not as significant) as the government suggests. In a majority of the cases in which these match probabilities have been admitted, the defense failed to present evidence of the controversy among scientists which has since been recognized in the NRC Report and described in detail in Barney.¹⁶ Indeed, the articles in Science magazine which focused attention on the controversy had not been written at the time that the cases on which the government relies were decided.¹⁷

In Commonwealth v. Lanigan, 413 Mass. 154, 596 N.E.2d 311 (1992), the court, after discussing the NRC’s recognition in its report of the current debate among population geneticists, concluded that

the lively, and still very current, dispute described above regarding the role of population substructure constitutes something much more than a lack of unanimity. We cannot say that the processes by which Cellmark and the FBI estimated the frequency of the defendants’ DNA profiles has found “general acceptance” in the field of population genetics. Accordingly evidence of the estimated frequencies of the defendants’ DNA profiles is not admissible. Because the frequency estimates are inadmissible, evidence of a match between profiles is also inadmissible.

Id. at 162-63, 596 N.E.2d at 316; (citation omitted). Similarly, in Bridgett, Judge Richter wrote that

while the Defendant’s contentions regarding the FBI’s RFLP procedure are without merit, the issues raised concerning the FBI’s calculation of probability estimates are meritorious. Several courts, including the Porter court, have excluded DNA evidence because of either the lack of consensus in the scientific community or the unreliability of probability estimates attached to the declaration of a match. Moreover, many scientific articles have been written on the issue both critical of and in favor of the calculation methodology employed by the FBI.

120 Daily Wash.L.Rptr. at 1704 (footnote¹⁸ and citations¹⁹ omitted). See also Vandebogart, supra, — N.H. at --, 616 A.2d at 493-94; State v. Houser, 241 Neb. 525, 545-50, 490 N.W.2d 168, 182-84 (1992); Commonwealth v. Cumin, 409 Mass. 218, 220, 565 N.E.2d 440, 442-45 (1991); State v. Pennell, supra, note 5, 584 A.2d at 517-20.²⁰ To the extent that the decisions of the court and the magistrate in Yee, 134 F.R.D. at 165, 202, are to the contrary, we respectfully decline to follow them, especially in light of developments since Yee was decided.

The government further argues that the FBI’s probability calculation should have been admitted because the defense objections to it go to its weight and not to its admissibility. As the trial judge noted, however, “the government ignores the fact that it is the probability feature which is at the very core of the DNA evidence.” Porter, 120 Daily Wash.L.Rptr. at 506. “Since a match between two DNA samples means little without data on probability, the calculation of statistical probability is an integral part of the process and the underlying method of arriving at that calculation must pass muster under Kelly/Frye.” Axell, supra, 235 Cal.App.3d at 866-67, 1 Cal.Rptr.2d at 430. “[W]e would not permit the admission of test results showing a DNA match (a positive result) without telling the jury anything about the likelihood of that match occurring.” Curnin supra, 409 Mass. at 222 n. 7, 565 N.E.2d at 442-43 n. 7; see also Vandebogart, supra, — N.H. at —, 616 A.2d at 494; Barney, supra, 8 Cal.App.4th at 816, 10 Cal.Rptr.2d at 742.

Since the probability of a coincidental match is an essential part of the DNA evidence, and since there is no consensus as to the accuracy of the FBI’s calculation, we decline to hold that the defense objections to that precise calculation go only to its weight. But see State v. Pierce, 64 Ohio St.3d 490, 494-97, 500-01, 597 N.E.2d 107, 111-12, 115 (1992) (distinguishing cases based on Frye and noting that Ohio does not follow Frye; court holds that objections to DNA evidence, which included prosecution experts’ calculations of odds of forty billion to one against a coincidental match, go to the weight of such evidence but not to its admissibility).

The lack of general acceptance among scientists of the proposition that the FBI’s “fixed bin” methodology is sufficiently accurate to support a coincidental match probability of one in thirty (or forty) million, however, does not compel the conclusion that no probability estimate at all may be presented to the jury. As we explain below, demonstration of the existence of consensus among the appropriate scientists as to a more modest calculation would be sufficient.

E. A More Conservative Consensus?

The parties and the trial judge focused their attention at the Frye hearing on the question whether, consistent with Frye, the prosecution was entitled to introduce expert evidence to the effect that the probability of a coincidental match was thirty (or forty) million to one. The judge correctly found that there was no general acceptance by the relevant group of scientists for the proposition that the FBI’s methodology is sufficiently accurate to support a calculation of these specific odds. There was no inquiry below, however, as to whether such a consensus existed in support of a more conservative figure.

“A criminal trial is not a game, but a quest for truth.” Womack v. United States, 350 A.2d 381, 383 (D.C.1976); see also United States v. Nixon, 418 U.S. 683, 710 & n. 18, 94 S.Ct. 3090, 3108 & n. 18, 41 L.Ed.2d 1039 (1974). “The twofold aim of criminal justice is that guilt shall not escape or innocence suffer.” Nixon, supra, 418 U.S. at 709, 94 S.Ct. at 3108 (quoting Berger v. United States, 295 U.S. 78, 88, 55 S.Ct. 629, 633, 79 L.Ed. 1314 (1935)). In the present case, the prosecution seeks to introduce the DNA evidence to corroborate an anticipated identification of Kevin Porter by the complaining witness. “[W]ith today’s technology, which uses 3-5 loci/²¹] a match between two DNA patterns can be considered strong evidence that the two samples came from the same source.” NRC Report, supra, at 74. There is thus no doubt that such evidence is strong; the only real question is: how strong? If the odds against a random match are substantial, then it would be a remarkable coincidence, to say the least, if the complaining witness identified Porter as her rapist, but if the crime was nevertheless committed by someone else whose DNA just happened to match Porter’s with respect to each of four loci. “Coincidences happen, but an alternative explanation not predicated on happenstance is often the one that has the ring of truth.” Byrd v. United States, 614 A.2d 25, 32 (D.C.1992) (quoting Poulnot v. District of Columbia, 608 A.2d 134, 139 (D.C.1992)).

The odds against a coincidental match do not have to be thirty million to one for evidence of the match to be admissible. “[I]f the evidence offered conduces in any reasonable degree to establish the probability or improbability of the fact in controversy, it should go to the jury.” Home Ins. Co. v. Weide, 78 U.S. (11 Wall.) 438, 440, 20 L.Ed. 197 (1870); see also Martin v. United States, 606 A.2d 120, 128-29 (D.C.1991). Accordingly, “[population percentages on the possession of certain combinations of blood characteristics, based upon established facts, are admitted as relevant to identification.” State v. Washington, 229 Kan. 47, 59-60, 622 P.2d 986, 995 (1981) (0.6% of the population had defendant’s combination of blood factors); see also Commonwealth v. Gomes, 403 Mass. 258, 273, 526 N.E.2d 1270, 1279 (1988) (defendant among 1.2% of blacks in United States whose blood was consistent with evidentia-ry sample); Plunkett v. State, 719 P.2d 834, 841 (Okla.Cr.1986) (blood with characteristics of victim found in 0.48% of population); cf. Jones, supra, 548 A.2d at 44-45; but see State v. Kim, 398 N.W.2d 544 (Minn.1987) (contra, expounding minority rule); Rivera v. State, 840 P.2d 933, 942, No. 90-163 (Wyo. Oct. 30, 1992). These principles apply with equal force in DNA cases. Smith v. Deppish, 248 Kan. 217, 235-39, 807 P.2d 144, 157-59 (1991); Martinez v. State, 549 So.2d 694, 696-97 (Fla.App.1989); People v. Mohit, supra, 579 N.Y.S.2d at 993, 999.²²

In Mohit, the court hit the nail on the head in the following revealing passage:

If, as will be found in this case, a reliable match is made, but the probabilities attached are not reliable, should the proponent of the evidence be denied its admissibility altogether? Shouldn’t the jury know that there was a match and that the possibility of the perpetrator being someone other than the defendant is remote, even if it is difficult to say precisely how remote? If, for example, many in the scientific community would agree that a probability is 1 in 1,000,000, but others, reasonably doubting the accuracy of that number, can only agree to 1 in 100,000, shouldn’t a jury at least know the more conservative number? The defendant could not reasonably claim prejudice, and the prosecution could still bring important and reliable evidence to a jury’s attention.

579 N.Y.S.2d at 993.

After describing the disagreement among scientists which we have discussed at pages 638-639, supra, the judge in Moh-it stated that “the fact that it is difficult, given the present state of knowledge, to be precise, does not mean that conservative numbers cannot be used.” Id. 579 N.Y.S.2d at 999. Expressing confidence that “no credible segment of the scientific community would claim that the probability estimates ... in this case or any other could be higher than 1 in 100,000, id.23 (rather than 1 in 67,000,000 as claimed by the People), the judge held that the prosecution would be permitted to introduce evidence of the match, but that the FBI probability estimates would be limited in accordance with his decision. Id. We agree with this analysis.

F. Identifying the Consensus.

We leave to the trial judge the initial determination as to whether the requisite consensus now exists for a conservative statement of the probability of a coincidental match and, if so, what the probability is in the present case. We do so, in part, because this issue was not focused upon by the court and counsel during the Frye hearing.²⁴ Although it appears improbable, in light of recent events, that no conservative consensus can be found, it would be unfair to Porter for the appellate court to proclaim ex cathedra the precise (and minimal) probability of a coincidental match without a crossing of swords on the issue in the court below.

The information presently before the court suggests, however, that the odds against a match being the result of a coincidence are extremely high even if one uses the most conservative reasonable calculation.

In Barney, supra, the court admitted evidence that the blood of one of the defendants and the evidentiary sample in his case “shared an unusual blood type found in only 1.2 persons out of 1000 in the Black population.” 8 Cal.App. 4th at 828, 10 Cal.Rptr.2d at 748. In holding that the trial judge had committed error (but harmless error) when he admitted evidence that the probability of a coincidental DNA match was one in two hundred million, the court recognized

the irony in finding a frequency estimate of 1.2 in 1,000 to be significant while excluding DNA evidence which would have to be in error by five or six orders of magnitude — a degree of error not even claimed by Lewontin and Hartl — to approach a reduced equivalence. This does not, however, undermine our finding of no general acceptance, but rather underscores the need to find a low threshold of agreed statistical significance for DNA evidence.

Id. at 826 n. 6, 10 Cal.Rptr.2d at 748 n. 6.²⁵

In Bridgett, Judge Richter rejected the government’s proffered probability evidence, agreeing with Judge Kennedy that the prosecution had failed to demonstrate general acceptance of the FBI’s methodology. The judge nevertheless held that a more conservative estimate based on the NRC Report’s “modified ceiling principle” was admissible. Having noted the standing and impartiality of the authors of that study,²⁶ the judge wrote as follows:

This present lack of consensus should not, however, exclude probative DNA evidence if the deficiencies can be corrected through the use of conservative estimates. Indeed, the NAS report assumed that certain populations may be stratified or substructured and that such a phenomenon would not be evident in the frequencies employed by the FBI since the Hardy-Weinberg rule is a poor test to detect disequilibrium. The report concluded, however, that such deficiencies should not function to completely exclude DNA evidence from the courtroom, but may be corrected by ensuring that the probability estimates of a coincidental match between the evidentiary and known samples are “appropriately conservative.”

The report formulated a methodology, the ceiling principle, which calculates the chance of a random match and incorporates the criticisms leveled by opponents of the FBI’s methodology. Since the ceiling principle may not be employed until the proper population sampling is computed, the committee has formulated a modified ceiling principle: In effect, a more conservative version of the conservative ceiling principle. The modified ceiling principle may be employed at present since the frequencies are taken from existing databases. This modified formula requires that the largest frequency from the current databases be used for the defendant’s allele frequencies. Once this frequency has been determined, one calculates the 95% upper confidence limit, or applies a frequency of 10%, whichever is larger. The committee recommends the use of the 10% frequency floor to account for the un-sampled populations’ allele frequencies.

This Court finds this formula appropriate under Frye for determining the probability estimates to be applied to a match declaration.

120 Daily Wash.L.Rptr. at 1704 (footnotes and citations to NRC Report omitted).

No appeal from the decision in Bridgett is before us, and we do not at this point rule definitively on Judge Richter’s analysis and conclusion. On remand, the court and counsel should address the holding in Bridgett and its potential applicability in this case.²⁷

IV

CONCLUSION

For the foregoing reasons, the trial court’s order denying the government’s motion to introduce DNA evidence is vacated and the case is remanded to the trial court for further proceedings consistent with this opinion.

So ordered. 28

1 . The government later amended its probability estimate to one in forty million. Now, before this court, it essentially takes the position that the figure of one in 270,000 may also be presented to the jury.

2 . Porter’s initial brief, for example, is 241 pages long, not including the fifty-seven exhibits appended to it.

3 . We need not here determine how small that fraction may be, since it does not appear that the trial court will be dealing with probabilities less than one in many thousand. Moreover, in the present case, the evidence is offered to corroborate the identification of Porter as the assailant, and the entire prosecution case does not depend on the expert testimony. We emphasize that we are dealing here with the admissibility of the evidence, and not with its sufficiency, standing alone, to convict a defendant.

4 .In order to keep this opinion within reasonable bounds, we adopt, but do not set forth de novo, the trial judge's comprehensive summary of the testimony of the six prosecution experts and two defense experts who gave evidence at the Frye hearing. See Porter, supra, 120 Daily Wash.L.Rptr. at 485-87, 89-93. We note that the judge also considered the extensive testimony of expert witnesses for the prosecution and for the defense in United States v. Yee, 134 F.R.D. 161 (N.D.Ohio 1991), as set forth in the unusually detailed report of the federal magistrate in that case. See Porter supra, 120 Daily Wash.L.Rptr. at 495 n. 47.

5 . The technical details of fixed bin analysis are not easy for a lay person to comprehend. In light of our disposition of this case, we do not find it necessary to try to explicate in our own words such esoteric principles as "Hardy-Weinberg equilibrium,” or "linkage disequilibrium." See State v. Pennell, 584 A.2d 513, 517 (Del.Super.1989), on rehearing, id. at 521-22; (defining Hardy-Weinberg equilibrium). For more detailed descriptions of the technology of probability estimates, see Porter, 120 Daily Wash.L.Rptr. at 485; and United States v. Bridgett, 120 Daily Wash.L.Rptr. 1697, 1700-01 (Super.Ct.D.C.1992).

6 . Judge Burgess’ opinion in Roy has been characterized by this court as "cogent ... thoughtful and comprehensive." Jones, supra, 548 A.2d at 45.

7 . We will take judicial knowledge of the scientific fact that the earth is round. At the same time, we know there are still individuals who claim to be scientists who have other theories, even to the extent of holding that instead of living on the outer surface of a globe we live within a globe, and that there are within it sun, moon, stars and all the heavenly bodies which we observe.

McKay v. State, 155 Tex.Crim. 416, 419, 235 S.W.2d 173, 174 (1950).

8 . Cf. Yee, supra, 134 F.R.D. at 197 (the question is whether "the pertinent scientific community generally accepts the ability of the FBI’s protocol and procedures to ... provide a scientifically acceptable estimate of the relative rarity of the particular pattern in the [relevant] population.”)

9 . “In objecting to the admission of this evidence, the defendant has adopted a 'scorched earth’ strategy, one which leads him to object to virtually each and every aspect of this evidence and, even, to question the motives of its proponents.” Porter, 120 Daily Wash.L.Rptr. at 501.

10 . Porter challenged, inter alia, the following:

1) the FBI’s practice of declaring a match by both visual and computer-assisted means;

2) the FBI's failure to replicate test results;

3) the inability of the FBI to precisely measure the VNTR;

4) the absence of standards governing forensic DNA typing;

5) the FBI’s purported lack of a blind proficiency testing program; and, in light of the foregoing,

6) the alleged existence of a significant danger that a false positive could be called a match.

See Bridgett, supra, note 5, 120 Daily Wash.L.Rptr. at 1701; see also Mohit, supra, 579 N.Y.S.2d at 994-95, discussing the use of Ethidi-um Bromide during gel electrophoresis, a process described in Jakobetz, supra, 955 F.2d at 792. The recent decision of the Supreme Court of Minnesota in State v. Jobe, 486 N.W.2d 407, 419-20 (Minn.1992) contains a concise and persuasive analysis of the objections commonly offered to the FBI’s RFLP matching procedure.

11 .E.g., the government displays a "virtual mania to get this evidence before a jury," Appellee’s brief at 40 n. 95; the FBI “is as disingenuous as its terminology is artful,” id. at 41; the government’s position is “audacious,” id. at 42; "the so-called ‘blind’ proficiency testing ‘program’ of the FBI is a sham,” id. at 50; ”[f]or the government to make that proffer in the instant litigation borders on the absurd," id. at 56; “the hyperbole of the FBI and its fellow travelers [!!] in the DNA lobby,” id. at 82 (this must be one of the few occasions on which the FBI has been “red-baited”); the FBI is ”[l]ike the evangelist quoting his own scripture as authority ...,” id. at 94; “the entire ‘galaxy’ of pro-FBI ‘stars,’ ” id. at 135; "nudum dictum,”id. at 139; pro-DNA scientists’ “concatenation of broad, flat assertions without supporting authority are simply too ponderous to swallow whole,” id. at 145; the NRC Report is not a “papal encyclical,” id. at 191; NRC’s “suggested practice which may be ‘robust’ scientific theory but which is ‘moribund’ due process of law.” Id. at 206.

12 . But cf. People v. Pizarro, 10 Cal.App.4th 57, 95-96, 12 Cal.Rptr.2d 436, 461 (5th Dist.1992) (trial court must determine whether private laboratory’s RFLP protocol is generally accepted as reliable within scientific community).

13 . In its brief on appeal in the present case, the government repeats its argument below that

the peer-reviewed scientific articles in press at the time of the Frye hearing sufficiently demonstrated the general acceptance of fixed bin analysis. More articles have either appeared or been accepted for publication since that time, however, making even more apparent the overwhelming weight of supporting scientific authority. Of the articles and letters in scientific journals that discuss the human population genetics component of forensic DNA analysis, at least 18 peer-reviewed articles and ten letters support the methodology at issue, while only 6 articles and commentaries and 7 letters question it. Further reflecting this broad support, over 45 scientists appear as either authors or co-authors on the "favorable” articles, while only a dozen scientists authored or co-authored the critical articles or letters to the editor.

We think that in the foregoing passage, the government asks this court to choose between scientists on the basis of rather unimpressive numbers, and thus to make precisely the kinds of determinations as to which Frye requires a consensus of experts.

14 . In light of the "abstruse, intensely technical [scientific] standards involved,” Hopkins v. State, 579 N.E.2d 1297, 1303 (Ind.1991), courts are well advised not to pick sides in scholarly controversies between eminent scientists about molecular biology or population genetics. As one scholar has observed, "[t]he theory and technology of DNA far surpass everyday knowledge. In fact, only those specifically trained in molecular biology and chemistry [and population genetics] can even begin to understand the concepts involved." Norman, DNA Fingerprinting: Is It Ready For Trial, 45 Univ.Miami L.Rev. 243, 243-44 (1990). We, therefore, elect instead to heed Lord Mountararat’s musical commentary on the House of Lords:

And while the House of Peers withholds Its legislative hand,

And noble statesmen do not itch To interfere with matters which They do not understand,

As bright will shine Great Britain’s rays As in King George’s glorious days!

William Gilbert & Arthur Sullivan, Iolanthe, Act II (1882). The hereditary peerage is not the only branch of government which can benefit from his lordship’s counsel.

15 . People v. Kelly, 17 Cal.3d 24, 130 Cal.Rptr. 144, 549 P.2d 1240 (1976).

16 . In Spencer v. Commonwealth, 238 Va. 275, 289-91, 384 S.E.2d 775, 783 (1989), cert. denied, 493 U.S. 1036, 110 S.Ct. 759, 107 L.Ed.2d 775 (1990), a case on which the government relies, defense counsel acknowledged that DNA tests are accepted as reliable and that he was "unable to find or produce one qualified expert to debunk either the theory of DNA printing or the statistics generated therefrom.” But see the very recent decision in Satcher v. Commonwealth, 244 Va. 220, 421 S.E.2d 821, 833-34 (1992), in which the Supreme Court of Virginia adhered to its Spencer holding in the face of a much more sophisticated defense presentation.

17 . "Whatever the merits of the prior decisions on the statistical calculation process ... the debate that erupted in Science in December 1991 changes the scientific landscape considerably and demonstrates indisputably that there is no general acceptance of the current process.” Barney, supra, 8 Cal.App.4th at 820, 10 Cal.Rptr.2d at 744.

18 . In the omitted footnote, Judge Richter cited a number of other decisions, some of them unreported, in which evidence of probabilities was excluded for lack of scientific consensus.

19 . The citations included the Lewontin-Hartl Chakraborty-Kidd brouhaha in Science magazine.

20 . Cases in which the prosecution's probability calculations were excluded but more conservative estimates were admitted are discussed in Part III D, infra.

21 . In this case, four loci.

22 . We disagree with Porter’s contention that admission of statistics as to the minuscule probability of a random match is unduly prejudicial. “The defendant fails to persuade us that the admission of DNA identification evidence will lead to an improper trial by mathematics.” People v. Adams, 195 Mich.App. 267, 278, 489 N.W.2d 192, 198 (1992). As the court stated in Martinez, supra, 549 So.2d at 697,

[i]f we adopt Martinez’s position, we will exclude statistical probability testimony where it is the most cogent_ Indeed, [the defense logic] might lead to the exclusion of fingerprint evidence, which also is based on the mathematical theory of probabilities that the chance of two individuals bearing the same fingerprint (or prints) is so infinitesimally small as to be negligible.

In State v. Brown, 470 N.W.2d 30 (Iowa 1991), the court, after quoting from the foregoing passage in Martinez, observed that "statistical evidence does not remove the issue of identity from the jury, which is free to disregard or disbelieve expert testimony.” Id. at 33; accord, Adams, supra, 195 Mich.App. at 278-80, 489 N.W.2d at 198. See also State v. Garrison, 120 Ariz. 255, 258, 585 P.2d 563 (1978) (en banc) (trial court properly admitted testimony that the teethmarks on the decedent’s breast were consistent with those made by Garrison and that the chances of another person having made them were about eight in one million).

23 . Other cases in which probability calculations more conservative than those proposed by the prosecution were admitted into evidence include Caldwell v. State, 260 Ga. 278, 288-89, 393 S.E.2d 436, 443-44 (1990) and Wesley I, supra, 140 Misc.2d at 331-32, 533 N.Y.S.2d at 659, recently affirmed in Wesley II.

24 . "[P]arties may not assert one theory at trial and another theory on appeal." D.D. v. M.T., 550 A.2d 37, 48 (D.C.1988) (quoting Hackes v. Hackes, 446 A.2d 396, 398 (D.C.1982). "Points not asserted with sufficient precision [in the trial court] to indicate distinctly the party's thesis will normally be spurned on appeal.” Hunter v. United States, 606 A.2d 139, 144 (D.C.1992) (quoting Miller v. Avirom, 127 U.S.App.D.C. 367, 369-70, 384 F.2d 319, 321-22 (1967)). These principles apply as rigorously to the government as they do to a criminal defendant who faces the loss of his liberty. Even on appeal, the government continues to rely principally on the argument that consensus exists as to a probability of one in thirty million — a notion which we emphatically reject in this opinion. (The government does make an alternative argument in its initial and reply briefs in support of a more conservative statement of the probability of a coincidental match.)

We think the question whether a more conservative consensus exists is nevertheless properly before us. First, the authoritative NRC Report, which was issued well after the Frye hearing, provides important support for use of a more conservative figure, as do several recent decisions issued since Judge Kennedy’s ruling, including Mohit and Bridgett. The judge anticipated that the NRC Report might change things, and he should be given the opportunity to determine if it has done so. Second, admission of evidence of a coincidental match probability of, say, one in thirty thousand is arguably "lesser included” relief where the prosecutor has sought to elicit testimony that the odds are one in thirty million. Finally, the case is one of general public importance, and, as our first venture into the subject, has the potential for becoming a significant precedent in this jurisdiction. So long as procedural fairness is preserved — and we think our remand procedure preserves it, for Porter has had or will have an opportunity to address all relevant issues — it is imperative that a case in which so extensive a record has been developed be decided in conformity with correct legal principles.

25 . In Barney, the calculation which lacked consensus had already been received in evidence. The court was therefore in no position to direct that a more conservative figure be placed before the jury. This was likewise true in Lanigan, supra, in which the court reversed a conviction after the admission of a calculation of one in 2.4 million for which there had been no showing of general acceptance in the scientific community. 413 Mass. at 156-58, 596 N.E.2d at 312-13.

26 . The National Academy of Sciences (NAS) published [its] report on forensic DNA typing in the interim between the decision rendered in the Porter case and the oral arguments held in this case. That report reinforced the general reliability of forensic DNA typing and, al- • though it noted the dissension in the scientific community over the calculations employed by DNA typing laboratories, the NAS provided an alternative calculation scheme. This definitive report is central to the Court's determination. A review of the committee members reveals that the committee itself is a distinguished cross section of the scientific community. Indeed, committee members included Dr. Eric Lander, an outspoken critic of the FBI’s methodology and one whose views were forthrightly promoted by the defense in this case and in Porter. Thus, that committee’s conclusion regarding the reliability of forensic DNA typing, specifically RFLP analysis, and the proffer of a conservative method for calculating probability estimates can easily be equated with general acceptance of those methodologies in the relevant scientific community. Indeed, in terms of the spectrum of existing scientific scholarly opinion, the report falls well towards the cautious end.

120 Daily Wash.L.Rptr. at 1702 (footnotes omitted).

27 . We note that in three very recent decisions in which it was held that FBI match probability calculations had been improperly received, the courts have expressly endorsed what the Supreme Judicial Court of Massachusetts has described as "[t]he national call for considered, conservative approaches to DNA testing, such as the use of ceiling frequencies.” Lanigan, supra, 413 Mass. at 163, 596 N.E.2d at 316; accord, Barney, supra, 8 Cal.App. 4th at 821-22, 10 Cal.Rptr.2d at 745; see also Vandebogart, supra, — N.H. at -, 616 A.2d at 494-95 (remanding to trial court for a determination whether there is general acceptance of NRC's recommended ceiling principle). Judge Richter’s general approach in Bridgett is thus in excellent company.

28 . The parties and amicus have asked us to address a number of procedural and other issues which we decline to reach. In light of our basic holding, however, we do not think that extensive Frye hearings will be necessary in future DNA litigation. See, generally, Jones, supra, 548 A.2d at 43-46. Some pretrial inquiry may be necessary in some cases to identify a conservative estimate of the probability of a random match. If there is some persuasive reason to doubt that the FBI or private laboratory has conscientiously followed its own protocol and conducted the procedures correctly, however, the trial court should also hold a pretrial hearing on that limited issue. See, e.g., State v. Jobe, 486 N.W.2d 407, 419 (Minn.1992); People v. Castro, 144 Misc.2d 956, 977-78, 545 N.Y.S.2d 985, 998 (Supreme Ct. Bronx County 1989).