Proving innocence, solving cold cases, frequently depend on DNA collection and preservation

Much of the focus at the 3rd annual "Actual Innocence" conference I attended last week centered on DNA testing which has led to more than 200 recent exonerations nationwide, so I thought I'd share with readers a few items of interest from my notes on the topic.

Perhaps unsurprisingly, Jim McLaughlin of the Texas Police Chiefs Association told the crowd that in an ideal world, he'd like to see every infant DNA swabbed at birth. (Why not just tag our ears like cattle, Jim, or inject a RFID chip under our skin and be done with it?)

Other speakers described pressures by law enforcement to expand the national DNA database by various means, and a handout in the backup material from USDOJ encouraged expanded use of DNA in property crimes. From a "CSI Effect" perspective that may sound like a good idea, but I don't see how it's pragmatically possible; the labs are overwhelmed trying to fulfill their functions now.

CODIS is the name of the software housing the national DNA database, to which 44 states contribute specimens from all certain convicted felons (see Texas' statute). Different states have different practices, but in Texas (and 10 other states) DNA swabs are taken upon arrest and entered into the system. Same for federal arrestees. Since its implementation, CODIS identified a possible match (not necessarily a defendant) in 2,238 total investigations as of March 2008, and in 50,000 investigations nationwide.

Three states allow the defense bar access to CODIS, which would certainly make it easier to check innocence claims or pursue independent investigatory paths from police.

A couple of speakers emphasized that scientists don't actually "match" DNA, but estimate a statistical probability they're the same, which is a slightly different beast. Fingerprints, it was pointed out, previously were considered "gold standard" evidence but their infallibility has increasingly come under fire. In addition, HPD crime lab director Irma Rios emphasized how frequently DNA evidence is contaminated or mixed with other DNA at crime scenes in ways that damage the evidence or make it unusable.

Some attention was paid to the issue of swabbing family members when DNA appears to be "close" to a suspect but doesn't exactly fit. Forensic specialists identified several best practices they said "should" be followed in such instances, but gave no information as to whether these are the practices in Texas' DNA sampling program. E.g., departments by policy should destroy DNA swabs from innocent family member or other suspects, and familial swabs should not be uploaded into local DNA databases at all. Some agencies require informed consent to get DNA, but it's legal to lie to get DNA samples, DNA in someone's trashcan is fair game, and you don't need probable cause to take a DNA sample under current law, the gathering was told in a seminar titled DNA 101.

The legal eagles among you may be interested that the Supreme Court recently granted cert (meaning they agreed to hear the case) in Melendez-Diaz v. Massachussetts (07-591), which will decide whether a forensic lab report is "testimonial" evidence subject to the "Confrontation Clause" in the US Constitution, as set forth in the Crawford decision. (For reasons that will become clear when I discuss Dr. Bill Tillstone's talk, I think a lab report decidedly IS testimonial evidence, but readers will be shocked to learn that SCOTUS and I do not always agree.)

It was also suggested there could be Brady issues (meaning it could violate a prosecutor's duty to disclose exculpatory evidence) if defense counsel isn't allowed access to CODIS, though the question lacks the immediacy of the pending SCOTUS confrontation decision.

Evidence gathering and preservation is particularly important in DNA cases. (Pictured at left is the New Orleans evidence room, via the Denver Post.) The only reason so many exonerees have surfaced in Dallas is that the county kept old DNA samples. Elsewhere they've been destroyed, though few people believe the same problems that cause wrongful convictions in Big D don't occur elsewhere. In San Diego, according to one speaker, DNA evidence was destroyed in 3/4 of old cases. (In Houston, regular readers will recall, the DA's office to this day frequently requires destruction of DNA evidence as part of a plea bargain, which avoids anyone going back to check old cases.)

Susan Green, a reporter with the Denver Post, spent a year investigating evidence destruction for a major newspaper series on the topic. (See the complete series.) The issue comes up in two ways, she said: Proving innocence and solving cold cases. She called the system under-regulated, and said local authorities routinely destroy evidence in old cases, including thousands of rape kits.

Legislation currently moving in the Colorado state legislature "would grant new trials to criminal defendants in cases where DNA evidence was thrown out despite a court order requiring it be saved for testing." That would be a strong deterrent to negligence in evidence preservation, don't you think?