DNA technology is revolutionizing police work, and the criminal- justice system is struggling to catch up with it.
As the science - which can extract a person's genetic code from skin, hair, or fluids - is honed to near-precision, states are reconsidering rules of prosecution forged in an era of old- fashioned detective work.
Just last week, New York police beat a five-year statute of limitations by a matter of days to indict a serial rapist based solely on a DNA sample. The suspect's name is still unknown. Also, officers in White Plains, N.Y., used DNA to charge a jailed bank robber with a 21-year-old murder.
Now, several states are abolishing statutes of limitations on many violent crimes so that never-solved cases can be put to the scrutiny of DNA testing.
While prosecutors are delighted at the prospect, critics say it could wreak havoc, introducing what could be contaminated, poorly kept evidence, and asking witnesses to recall events that occurred years, if not decades, ago.
Either way, the new laws could herald a significant shift in law- enforcement priorities, as more money is sought to help overtaxed DNA units reopen old cases. Beyond that, the moves indicate how DNA research is becoming an ever-more indispensible tool in all areas of law enforcement.
New Jersey, Nevada, and Florida have already repealed time limits for charging sexual assault. Other states, including New York, are considering scrapping time limits on felonies such as manslaughter, rape, and robbery.
Defense lawyers and civil libertarians oppose allowing old evidence to be tested for DNA. The key issue is how the DNA samples have been handled and preserved over the years. In the O.J. Simpson case, for instance, the prosecution's case unraveled when the defense showed that some of the evidence had been sloppily handled.
The same thing is true in sexual-assault cases, critics say, where police call the preserved evidence "rape kits."
"We have no idea how these kits have been stored, whether the evidence has been degraded," says Kathryn Kase, president of the New York Association of Criminal Defense Lawyers.
DNA advocates agree proper handling can be a problem.
"You can't drag bodies through the evidence and expect it not to be contaminated," says Howard Safir, New York City police commissioner. But he says law-enforcement officials are learning to handle DNA evidence reliably: "It's not brain surgery."
Older kits were packaged before police followed strict protocols, so Mr. Safir says prosecutors would have to establish at trial how evidence was handled.
Other concerns raised by opening old cases have nothing to do with DNA.