Around the country, testing of rape evidence and the collection of DNA material from inmates is routine now.
Using unusually strong language, the court declared itself "struck by the blanket and indiscriminate nature" of the police's policy of holding DNA material indefinitely in its database.
Mr. Verchick said after yesterday's hearing that he thought the chance that the DNA material would yield a usable match was remote.
But he said painstaking work is required to extract uncontaminated DNA material without damaging a body that is already in bad condition.
"For this case to rest, it's very important to re-examine that DNA material and find out whose DNA profile it really is," Hall said.
But Israel's forensic lab did not confirm his identity until today, after receiving DNA material from Mr. Sharif's relatives in Britain, the lab said.
In some cases, forensic scientists have been able to obtain evidence of who made the bomb through a fingerprint or DNA material left on an explosive part.
The same experts said the biggest challenge in using DNA material in an investigation was finding enough of it to read on a piece of physical evidence.
In looking at these populations with the available evidence (skeletons, DNA, material cultures, languages), the tendency has been to think of them as discrete peoples; otherwise they would not be identifiable as different from one another.
Turi King, a Leicester University geneticist, said this week that if she could gather enough DNA material from the brothers' skeletons to establish a match with that from Richard III, it could show that they were related.
In a pretrial hearing yesterday, a prosecutor, Joel J. Seidemann, an assistant district attorney, told the judge that DNA material found under Mr. Peterson's fingernails had been preserved for 17 years.
