Several senior law enforcement officials gave cautious support to some of the reforms proposed yesterday in a set of bills that would make it easier for convicted criminals to use DNA evidence to prove their innocence.

The bills were written in response to the exonerations of nine men serving sentences in New York during the past 16 months. The reforms include requiring statewide standards for evidence preservation, allowing people who plead guilty to a crime to have their DNA tested, and creating a state “Innocence Commission” to investigate wrongful convictions.

“The criminal justice system far more often than not does work appropriately, but clearly it is not infallible,” the president of the New York State District Attorneys Association, Michael Bongiorno, said. “There is a need for resources to be used to upgrade police departments’ ability to store evidence.”

Mr. Bongiorno, the district attorney of Rockland County, said the number of exonerations was a fraction of the number of valid convictions.

The National District Attorneys Association supports DNA testing at any stage of a proceeding, as long as it has the potential to prove someone’s innocence, a vice president of the organization, Joshua Marquis, said.

Barbara Thompson, a spokeswoman for the Manhattan district attorney, Robert Morgenthau, said the district attorney’s office could not comment specifically on the bills until it had thoroughly reviewed them, but that Mr. Morgenthau believes DNA testing is a tool that can both convict the guilty and exonerate the innocent.

“We would welcome any proposal that maximizes the use of DNA technology,” Ms. Thompson said.

Jerry Schmetterer, a spokesman for the Brooklyn district attorney, Charles Hynes, said: “The district attorney certainly is in favor of anything that would expedite procedures for the release of innocent persons serving time for a crime he or she did not commit.”

Representatives for the Staten Island, Bronx, and Queens district attorneys said they would not comment until they had thoroughly reviewed the bills.

The sponsors of the bills include Assemblyman Joseph Lentol, a Democrat of Brooklyn, and Assemblyman Michael Gianaris, a Democrat of Queens.

Together with the Innocence Project, a group that helps prisoners get DNA tests to prove their innocence, the two lawmakers yesterday presented the bills outside an NYPD evidence storage facility at One Pearson Place in the Long Island City section of Queens.

The facility came under scrutiny after the exoneration of Alan Newton last summer. While he was serving 22 years of a sentence for rape, robbery, and assault, police told Mr. Newton three times that his evidence was lost or destroyed. A Bronx assistant district attorney eventually helped find it, but a co-director of the Innocence Project, Barry Sheck, said the facility was a symbol of antiquated evidence storage and its consequences.

The police commissioner, Raymond Kelly, sent out a request for proposals to update the department’s facilities last year. A police spokesman, Deputy Commissioner Paul Browne, declined to comment yesterday.