E-Mail This Article to a Friend Scientific uncertainty Romney’s death-penalty plan leaves much room for doubt. Plus, no due process for ‘enemy combatants.’ BY HARVEY A. SILVERGLATE AND CARL TAKEI

THE HEART OF the 29-page report issued Monday by Mitt Romney’s Governor’s Council on Capital Punishment is its proposal that any Massachusetts death-penalty scheme contain "a requirement of scientific evidence to corroborate guilt." While the most reliable proof in this category would be DNA evidence, other forms of scientific physical evidence would suffice as well, such as "photographs, video- and audiotapes, fingerprints, and certain impression evidence (e.g., some footwear impressions, tire impressions, tool marks, firearms-related impressions, and other physical pattern matches)."

If this is the best the council can do, then it has failed to achieve the Romney administration’s stated goal — a system where there is "no doubt" as to the defendant’s guilt and where (here the weasel words creep in) the result is "as accurate as humanly possible" (emphasis added). Rather than pursue this unattainable objective, we should continue to ban capital punishment, while improving the criminal-justice system generally by establishing an Innocence Commission to examine how each wrongful conviction has come about and seek to prevent recurrences. (See "Blinded with Science," News and Features, October 10, 2003; "What Have We Learned?", News and Features, November 14, 2003; and "Let Us Now Praise Framed-Up Men," News and Features, April 9.)

Unfortunately for pro-death-penalty forces in the Commonwealth, the council’s proposal suffers from an obvious flaw. DNA can provide powerful evidence for exonerating a suspect (and has revealed numerous wrongful convictions in Massachusetts and across the country), but it is considerably less reliable as surefire evidence of guilt. The council implicitly recognizes this when it notes that DNA must "connect the defendant to either the location of the crime scene, the murder weapon, or the victim’s body" in a way "that strongly corroborates the defendant’s guilt" if it is to provide the "conclusive scientific evidence" that will support the death penalty. The report gives an example of a situation where DNA evidence that "links" a person to a murder victim might not establish guilt of a crime: "For example, in a case where the defendant and the victim were spouses or otherwise intimates, a link between the defendant and the victim’s body may be virtually inevitable, and, therefore, may not ‘strongly corroborate’ the defendant’s guilt."

Let’s consider the most obvious case where this might be problematic: the rape-murder of a married woman. Suppose the victim’s husband’s DNA is found in semen in the deceased’s vaginal canal. This would not link the husband to the rape-murder, since he and his spouse would have been "intimates" and the presence of his semen in her body would be "virtually inevitable." But suppose that the DNA of the next-door neighbor were also found in the victim. Such evidence might indeed be seen as a strong "link" between the neighbor and the murder — so the husband walks and the neighbor fries.

In this case, Romney’s death penalty nails the right person if the neighbor actually committed the murder. But consider a fairly common alternate scenario: the wife was having an affair with the next-door neighbor, with whom she had just been intimate when the husband came home from work early. The neighbor fled, but, in a rage, the husband murdered his wife. Under Romney’s "perfect" death-penalty scenario, the neighbor could still be indicted, convicted, and sentenced to death because the presence of his DNA in the victim was less readily explained than that of the husband.

As for the council’s suggestion that other forms of scientific and forensic evidence can also offer an unfailingly accurate basis for conviction, the example of fingerprint evidence indicates that the council is suffering from either excess chutzpah or a very short memory. It was just four months ago that Stephan Cowans (convicted, based on a thumbprint, of shooting a cop) was, after six and a half years in prison, exonerated by DNA evidence. After the DNA evidence cleared Cowans, the Suffolk County District Attorney’s Office re-analyzed the prints at the crime scene and found that — contrary to expert testimony given at trial — the prints actually did not belong to Cowans. A judge threw out the conviction, Cowans is now free, and that case is currently under investigation to find out what went wrong. But if Romney and his "experts" had had their way, would the defendant still be alive to enjoy his own vindication?

So much for the scientifically infallible death penalty.