ALBANY -- A change in state rules will allow forensic scientists to tell police when crime scene DNA is a near match to a convicted criminal in their database, indicating the perpetrator was probably a relative.

The state Commission on Forensic Sciences voted for the change this week. New York's data bank contains DNA profiles from nearly 341,000 offenders.

Denise O'Donnell, commissioner of the Division of Criminal Justice Services, said such partial matches have come up "infrequently" though they could provide leads to a serial rapist or killer.

"It's not a DNA hit, but an investigative lead," O'Donnell said.

Proposed regulations will be subject to public comment, she said. That process could take several months.

The New York Civil Liberties Union, citing potential for errors, said it threatens privacy and due process rights.

"A policy that implicates New Yorkers in a criminal investigation solely because they are related to someone with DNA in the state's data bank is a miscarriage of justice," said Donna Lieberman, NYCLU executive director.

Under the interim policy of the FBI, which manages the national DNA database with links to state information, partial matching is allowed among states that allow it, division spokesman John Caher said.

Under current New York regulations, if DNA evidence from a rape is compared against the data bank, scientists can only tell police if they get a perfect match, Caher said. Some scientists feel that puts them in an ethical bind, that they cannot tell police even if they think one of somebody's relatives is almost certainly a match, he said.

He said there have been some prominent cases elsewhere.

In North Carolina, Darryl Hunt spent 19 years in prison for a 1984 rape and murder he didn't commit. A DNA data bank search found a near match to a convicted felon, and that man's brother, Willard Brown, later confessed.