I find little to agree with Anna Quindlen about, but....

From Coffee Cup To Court

The release of an innocent man, the linking of several crimes, the conviction of the undeniably guilty: the extraordinary uses of DNA testing are all there, in that one case. More reliable than fingerprints or ballistics or the evidence of your lying eyes, the genetic fingerprint we humans leave everywhere in our wake is the best witness the criminal-justice system has ever had. And not just for prosecutors. Roughly one in four of the samples run through a federal databank exonerates a suspect, even when all other evidence suggests he is guilty.

This is the good side of DNA evidence. Unfortunately, she also presents an example of the downside:

Lots of the attention paid to DNA testing so far has been negative, the concerns about privacy rights and the defense high jinks and scientific gobbledygook of the O. J. Simpson case. But those who are worried that their genetic secrets will be used to deny them insurance coverage ought to be more concerned with that urine sample provided at work. Those worried about the rights of the accused should know that DNA testing does more than any other technique to protect the innocent. It’s the anonymity of the guilty to which it poses a threat.

Good example: the case recently in which a rapist was in jail in Wisconsin because of DNA evidence when yet another woman reported an attack. The DNA from the scene matched that of the imprisoned man. Had the DNA lied? No, the woman had. She’d been paid to take a sample of semen that had been smuggled out of jail and stage the rape to make the guilty guy look innocent.

As the required DNA samples get smaller and smaller, the possiblity of fraud and false evidence climbs. The procedures that police use to collect such evidence become more and more important, and too few departments are capable of properly collecting such evidence. (Never mind finding the lab, the technicians, etc.) I agree with her on the promise of DNA evidence; I am less happy about its universal application.