Opinion ID: 2276915
Heading Depth: 3
Heading Rank: 2

Heading: During Closing Argument, the Prosecutor Again Misrepresented the Import of the Commonwealth's DNA Evidence.

Text: This conclusion is underscored by portions of the prosecutor's closing argument to which Duncan objected. Twice during that portion of her [2] argument based on Johnson's testimony, the prosecutor went from quoting Johnson's conclusion that Duncan could not be excluded as a source of the DNA in SM's panties, to insisting that not excluded means included, to the bottom line: What is Errick Duncan's DNA doing in SM's panties? Counsel objected both times the prosecutor reached this bottom line assertion, and following the second objection the court admonished the jury to the effect that while the evidence had not established a direct, absolute match, both sides were allowed to argue reasonable inferences from the evidence. Duncan maintains that the prosecutor's argument went beyond reasonable inference and had the effect, like that of the improper cross-examination, of misrepresenting Johnson's testimony. For the reasons discussed above, we agree. [3] The problem is not that the evidence failed to establish a match between Duncan's profile and the profile obtained from the sample. The evidence established a match, or a partial match, at ten of the seventeen tested sites. But missing from the Commonwealth's proof was any testimony establishing the significance of that partial match. Johnson's testimony that Duncan could not be excluded as a source of the panty DNA said nothing at all about how likely or unlikely it was for such a partial match to occur, and most assuredly it did not say that Duncan was the source. By asking the jury to infer on the basis of Johnson's testimony that he was, the prosecutor sought to wring from that testimony a conclusion it could not reasonably yield. This concern was reflected in the 1992 report of the National Research Council's Committee on DNA Forensic Science. That report, titled DNA Technology in Forensic Science, emphasized that [t]o say that two patterns match, without providing any scientifically valid estimate (or, at least, an upper bound) of the frequency with which such matches might occur by chance, is meaningless. Id. at 301. It is meaningless, or, at most, of marginal value, for precisely the reason noted above: although the evidence of a partial match established that Duncan could not be excluded as a potential source of the panty DNA, without further evidence putting the match in some context of significance, statistical or otherwise, it does not establish that anyone can be excluded and so merely includes Duncan among the rest of the world as a potential source. For this reason, several courts have held that DNA match or non-exclusion evidence is inadmissible without reliable accompanying evidence as to the likelihood that the test could or could not exclude other individuals in a given population. Without the accompanying evidence, these courts note the jury have no way to evaluate the meaning of the result. Commonwealth v. Mattel, 920 N.E.2d at 856 (collecting cases). In Sholler v. Commonwealth, 969 S.W.2d 706 (Ky.1998), this Court rejected that per se exclusionary approach and held that bald DNA match or non-exclusion evidence was admissible as circumstantial evidence akin to blood type evidence: We view [the expert's non-exclusion DNA] testimony as similar to that of an expert who testifies that a defendant's blood type is the same as that of a blood sample found at a crime scene.... Such does not mean that the crime scene blood was the defendant's blood, but only that the defendant is not excluded as the source of the crime scene blood. Id. at 710. We adhere, with some reluctance, to that holding today, but emphasize the following qualifications. Matching blood types provide weak circumstantial evidence that the defendant was the source of the crime scene blood. The rarer the blood type the slightly better the evidence, but no blood-type evidence standing alone would serve to identify the defendant beyond a reasonable doubt as the source of the crime scene blood. The potential probative value of DNA evidence is vastly more powerful. Although theoretically a DNA match over a large number of polymorphic sites, such as the thirteen sites of the CODIS standard, does not conclusively identify a defendant as the source of crime scene DNA, when the odds of a random match begin to vanish in the mists of the unimaginably small, as they often do in such cases, for all practical purposes the defendant is identified, and that evidence, standing alone, would support such a finding. In such cases, the Maryland Court of Appeals has held, the expert need not couch his or her testimony in the theoretical language of mathematics, but may testify directly that the match proves, to a reasonable scientific certainty, that the defendant is the source of the crime scene DNA. Young v. State, supra . In conjunction with this vast probative potential, DNA evidence is also subject to vast misunderstanding and misuse. Although at times highly probative, it can also, as this case illustrates, be much more modestly probative or hardly probative at all. Where its significance falls along that spectrum is a matter dependent upon expert testimony, since lay jurors are not qualified to make the assessment on their own. Statistical evidence, if possible, is the best way to convey the strength of DNA evidence, but statistics may not always be available, and where it is not the expert may use other valid means to give some idea of the extent to which the DNA evidence narrows the field of possible sources. [4] Whatever avenue is chosen, the Commonwealth must abide by the limitations of its own proof and not make claims that its DNA evidence is more probative than the expert's testimony has shown it to be. In particular, if, as in this case, the Commonwealth relies on mere evidence of a partial match and non-exclusion without any other evidence of the match's significance, it may not, as it did here, ask whether the DNA evidence is wrong because it contravenes the defendant's version of events. Similarly, the Commonwealth may not, by underscoring the fact of the partial match, invite the jury to speculate that the match is actually more significant than the expert testified, or that evidence of the partial match by itself is sufficient to identify the defendant as the source of the crime scene DNA. These are not reasonable inferences from bare non-exclusion evidence and so are not fair game either for cross-examination or for closing argument. Because the Commonwealth failed to present any evidence of the significance of Duncan's partial DNA match other than the expert's non-exclusion testimony, its suggestion during Duncan's cross-examination and during closing argument that the DNA evidence pin-pointed Duncan was highly improper and, given the immense weight jurors are apt to accord DNA evidence, rendered Duncan's trial manifestly unfair. We are obliged, accordingly, to reverse Duncan's conviction and to remand for additional proceedings. Because Duncan's other claims of error raise issues that could recur at a retrial, we shall briefly consider them as well.