dna giveth but it sure don't taketh away

pspunk alerted me to a short article describing how some states are addressing the "problem" of prisoners being exonerated by dna evidence. as clayton neuman wrote this week in time magazine:

Justice, it seems, has an expiration date. Luis Diaz last month became one of a handful of Florida prisoners--and one of 99 nationwide--exonerated by DNA testing since 2000. But the 2001 statute that helped set him free after he spent 26 years in jail for rapes he did not commit is set to expire next week. After Oct. 1, when prisoners can no longer petition Florida courts for post-conviction DNA testing, their only hope will be to ask prosecutors (the people who put them in jail in the first place) to reopen their case. Prisoners in Ohio face a similar deadline at the end of the month. "It is quintessentially un-American for the very people who may have caused this kind of miscarriage of justice to be the people who decide whether DNA testing occurs," says Jenny Greenberg of the Florida Innocence Initiative.

Worse still, the four-year window in Florida that required the preservation of evidence for older cases--which may have predated reliable DNA testing--is also closing. And unlike California, which last year passed a law ensuring the preservation of evidence throughout an inmate's incarceration, Florida Governor Jeb Bush last month mandated that law-enforcement agencies need give only a 90-day notice before destroying evidence, which isn't much time given the low literacy rates among inmates and how hard prison protocol makes it for them to reach a lawyer. Six states have yet to address the issue of requiring the preservation of DNA evidence. And new hurdles could arise at the congressional level, where a bill threatens to restrict many prisoners from filing one last-ditch petition in federal court. All these moves are designed to keep courts from getting deluged with DNA-related requests by thwarting new technology with red tape.

if i read this correctly, it means that states are starting to destroy the dna evidence used to convict prisoners at one end, and then not allowing them to petition to have themselves tested at the other. i'm all for keeping our busy courts from "getting deluged with dna-related requests," but i find the asymmetry in power a bit troubling here. dna evidence is an invaluable tool for police and prosecutors, but shouldn't it also be available for the wrongly convicted? i'm sure that there are many "frivolous" requests for testing, since guilty as well as innocent prisoners have an interest in something (anything!) to "rule themselves out" as suspects. still, it seems only a slight exaggeration to see this trend as inverting justice blackstone's adage: better to imprison 10 innocent people than to let one guilty person go free.