In Commonwealth v. Lanigan,
At a bench trial in which the defendant stipulated to the evidence against him, including the DNA evidence, the defendant was found guilty of rape of a child and of indecent assault and battery on three minors. We granted the defendant’s application fоr direct appellate review and once again consider the admissibility of DNA test results. See Commonwealth v. Daggett,
1. The defendant argues that two motiоns for dismissal of the charges against him should have been allowed because of the denial of his right to a timely trial pursuant to Mass. R. Crim. P. 36,
The defendant contends that his motions for dismissal of the charges should have been allowed because three intervals of time should not have been excluded in the calculation of the date by which, pursuant to Mass. R. Crim P. 36 (b), he should have been tried. Only two of them require any analysis.
The defendant asserts that the one-year period consumed by the Commonwealth’s appeal in Lanigan I (from the allowance of his motion in limine to exclude DNA evidence) should have been counted in calculating the time within which rule 36 (b) prescribes that he should have been tried. Rule 36 (b) (2) (A) (iv) expressly excludes any period of delаy “resulting from interlocutory appeals.” This exclusion applies to appeals by the Commonwealth. See Commonwealth v. McCants,
The defendant also objects to the exclusion of the period of delay immediately following Lanigan I resulting from the presentation of, and deliberations on, the Commonwealth’s attempt to support the admission of DNA test results based
Certainly the fifty-three month span between the defendant’s arraignment and his trial is sufficient to invoke a cоnstitutionally-based speedy trial analysis. See Barker v. Wingo,
The defendant, who has been incarcerated throughout the pendency of the charges, did not move for dismissal of the charges on speedy trial grounds until more than two years after his arraignment, and now makes no claim that that motion was improperly denied. In April, 1992, while Lanigan I was pending in this court, and again in December, 1992, while a Superior Court judge had the post-Lanigan I admissibility question under advisement, the defendant again moved for dismissal. For reasons we have already set forth in discussing the defendant’s rule 36 argument, there were strong public interest reasons justifying the delay. See Barker v. Wingo, supra at 531; Commonwealth v. Edgerly, supra at 105. Moreover, the defendant agreed to various continuances and sought others. The record does not indicate the defendant’s zealous pursuit of his right to a speedy trial.
Most important is the fact that the defendant cannot shоw that he was significantly prejudiced by the delay. He stipulated to the Commonwealth’s evidence at trial and presented no evidence in his defense. There can be no showing that any memory faded or any witness disappeared. Indeed, the evidence against the defendant from prospective witnesses who knew him was substantial, quite apart from the DNA test results. It is true that the delay enabled the Commonwealth to support the admission of evidence showing the statistical
2. We come then to the admissibility of the evidence relating to the results of DNA testing. As we have already noted, a test comparing the defendant’s DNA and DNA obtained from the clothes of one of the victims indicated a match. Over the defendant’s objection, evidence of the mаtch and of its statistical significance was submitted to the judge as the trier of fact. Evidence of a match based on currently used testing processes is meaningless without evidence indicating the significance of the match. See Commonwealth v. Curnin,
The expert testimony concerning the probability of a random DNA match was based on what the Commonwealth argues is a conservative approach that, it says, overcomes the
The Commonwealth’s so-called conservative approach was recommended in a 1992 report by a committee of the National Research Council of the National Academy of Sciences, entitled “DNA Technology in Forensic Science” (hereinafter the NRC Report). The committee assumed for the sake of discussion that population substructure may exist and provided a method for estimating population frequencies in a manner that, in its view, would adequately account for it. NRC Report at 12. The committee recommended the use of what it called the ceiling principle, which it said was conservative in the sense that the estimated frequencies would be based on assumptions favorable to a criminal defendant. Id. at 13.
We have previously considered the admissibility of expert testimony concerning the significance of DNA test results that showed a match between the defendant’s DNA and DNA found at a crime scene. In Commonwealth v. Curnin, supra, we concluded thаt there was “no demonstrated general acceptance or inherent rationality” of the means used to arrive at the stated probability (59,000,000 to one) that someone other than the defendant would have the same alleles as were shown in the DNA tests. Id. at 222, 227. The court considered not only whether the Commonwealth had demonstrated that the community of scientists involved gen
We next considered the admissibility question in the earlier appeal in this case that led to our opinion in Lanigan I. Since the release of our 1991 opinion in Commonwealth v. Curnin, supra, the NRC Report had been released. That report noted that the question was considerably debated by population geneticists whether the databases used for determining probabilities were appropriate for the process used (i.e., the product rule). Lanigan I, supra at 162. We held in Lanigan I that the process used had not received general acceptance by population geneticists and upheld the pretrial ruling that the DNA evidence was not admissible. Id. at 162-163. We noted the recommendation of the NRC Report that for forensic purposes a “ceiling frequency” be used for DNA frequency calculations.
Several other courts have also noted the potential that the ceiling principle would resolve any admissibility problem because it would produce a conservative estimate (or, perhaps one should say, an overestimate) of the frequency with which a defendant’s DNA (or, more accurately, particular alleles) would appear in randomly selected population groups. See, e.g., State v. Barney,
Our test for the admissibility of expert testimony based on scientific knowledge has usually been the Frye test, “that is, whether the community of scientists involvеd generally accepts the theory or process. Frye v. United States,
The Commonwealth urges us to adopt the reasoning of Daubert v. Merrell Dow Pharmaceuticals, Inc.,
In its Daubert opinion, the Court recognized that general acceptance by the scientific community was a relevant factor in determining the admissibility of expert testimony based on a scientific theory or technique. Id. at 594. But such acceptance, the essential ingredient of the Frye principle, is not the sole test. Id. The Court thought relevant the question whether the theory or technique can be or has been tested. Id. at 593. Peer review and publication of the theory or process is pertinent but also not an indispensable predecessor of admissibility. Id. at 593-594. The Daubert opinion finds a requirement of reliability implicit in rule 702, which on its face uses helpfulness to the trier of fact as the test of admissibility of expert testimony based on scientific knowlеdge.
The general proposition set forth in the Daubert opinion seems sound, although that opinion gives little guidance for the application of that proposition to the facts of a given case. See id. at 598 (Rehnquist, C.J., concurring in part and dissenting in part). The expert’s opinion must “have a reliable basis in the knowledge and experience of his discipline.” Id. at 592. The overarching issue is “the scientific validity — and thus the evidentiary relevance and reliability — of the principles that underlie a proposed submission.” Id. at 594-595. The trial judge has a significant function to carry out in deciding on the admissibility of a scientific expert’s opinion.
We accept the basic reasoning of the Daubert opinion because it is consistent with our test of demonstrated reliability. We suspect that general acceptance in the relevant scientific community will continue to be the significant, and often the only, issue. We accept the idea, however, that a proponent of scientific opinion evidence may demonstrate the reliability or validity of the underlying scientific theory or process by some other means, that is, without establishing general acceptance. This consideration has some application to the issue in the case before us, but the parties’ significant аrguments bear on the acceptability of the ceiling principle by the relevant scientific community.
The ceiling principle was adopted to make irrelevant the dispute among population geneticists over the question whether the product rule may properly be used to express numerically the probability of finding a DNA match in a random selection of the appropriate population. Among those experts who support using the product rule, many of whom the Commonwealth cites in its brief, and among those experts who believe that the ceiling principle solves any problem in the use of the product rule, the answer given by the ceiling principle is, respectively, either irrationally conservative and thus absurd or a reasonable means of producing admissible probability evidence untainted by the potential problems of population substructuring. The great weight of
This is a rapidly developing field, and new understanding may be expected as more studies and tests are conducted. Judges must be willing and able to adapt to these changes. Criticisms of the ceiling principle largely call for more tests. Some criticisms suggest that the result in all instances may not be conservativе. None of the criticisms brought to our attention indicates that the ceiling principle produces a probability prediction in this case that errs to the defendant’s disadvantage. See Lempert, DNA, Science and the Law: Two Cheers for the Ceiling Principle, 34 Jurimetrics J. 41 (1993) (commenting on criticisms of the ceiling principle, in-eluding some on which the defendant relies [see note 5 above], and concluding that the criticisms are not fundamental and can be accommodated). Aрplication of the ceiling principle in this case increased the probability of a match from only one in more than 2,000,000 (Lanigan I, supra at 156) to a range of one in 311,000 to one in 108,000. We conclude that the Commonwealth has established the reliability of the process underlying its expert testimony on probability and thus the evidence of the probability of a DNA match in a randomly selected population was properly admitted.
Judgments affirmed.
Notes
There is no merit to the defendant’s argument that the post-Lanigan I proceedings should have been held before the judge who had ruled previously on the admissibility of DNA evidence in this case.
The defendant misreads the record in arguing that the judge who denied his second rule 36 motion for a dismissal excluded forty-five days, instead of the thirty days prescribed by rule 36 (b) (2) (A) (vii), for the period during which the defendant’s motion in limine to exclude DNA evidence was under advisement in the Superior Court.
For Sixth Amendment purposes, it has been said that the right to a speedy trial is “not primarily intended to prevent prejudice to the defense caused by passage of time.” United States v. MacDonald,
Citing the NRC Report at 3-13, we said in Lanigan I: “The use of a ceiling frequency, which would represent the greatest observed frequency of particular alleles within a given number of randomly selected population groups, automatically would provide for the greatest, and therefore most conservative, estimate of the frequency of a DNA profile. One of the principles behind the recommendation of a ceiling frequency is the notion that any error in calculating profile frequencies that is caused by population substructure should accrue to the benefit of the individual against whom the DNA testing is being used.” Id. at 163.
See Cohen, The Ceiling Principle is not Always Conservative in Assigning Genotype Frequencies for Forensic DNA Testing, 51 Am. J. Hum. Genetics 1165, 1166-1167 (1992) (suggesting that the ceiling principle does not always produce a conservative result, pointing to an example in which the result may be unfairly inculpatory, and urging exploration of alternative methods of estimating a match probability); Slimowitz, Violatians of the Ceiling Principle: Exact Conditions and Statistical Evidence, 52 Am. J. Hum. Genetics 314, 315, 322 (1993) (describing circumstances in which the ceiling principle can fail to be conservative and is not always mathematically reliable, and calling for more research); Krane, Genetic Differences at Four DNA Typing Loci in Finnish, Italian, and Mixed Caucasian Populations, 89 Proc. Nat’l Acad. Sci. USA 10583, 10583, 10586, 10587 (1992) (recommending more studies but commenting that “the interim ceiling principle [recommended by NRC report for use until more data are gathered] is a significant imprоvement over the conventional
