Governor Paterson, in hiring a Manhattan judge known for being pro-defendant as his top in-house lawyer, is signaling that he will move leftward from Governor Spitzer on criminal justice policy matters.

Mr. Paterson announced yesterday that Governor Spitzer’s counsel, David Nocenti, would be succeeded by Judge James Yates, a onetime Albany staffer who has spent the past decade presiding over criminal trials in Manhattan, and developing a reputation as a skeptic of police power.

Lawyers with knowledge of Judge Yates’s record are speculating that he will influence Mr. Paterson on various criminal justice policy initiatives left pending from the Spitzer administration, including a proposal to expand the state’s DNA database to cover a wider pool of criminals. Mr. Spitzer also initiated a wide review of the state’s sentencing laws and spoke in favor of the death penalty, which New York State currently lacks.

“This appointment may signal Governor Paterson’s intention to adopt a progressive criminal justice agenda,” a former prosecutor who has appeared before Judge Yates, Daniel Alonso, now of the firm Kaye Scholer, said.

The appointment of Judge Yates was unexpected, given that the two are not close associates. They overlapped in Albany for about six years in the 1980s and 1990s, when Mr. Paterson was a state senator and Judge Yates was counsel to Assemblyman Melvin Miller, who eventually became speaker. Mr. Paterson recalled working with Judge Yates on hate crime legislation, a source close to the governor said.

Judge Yates first got to the bench through an appointment by Governor Cuomo in 1992, and was later elected on his own.

“He doesn’t decide everything our way, but he’s a very good judge,” the Manhattan district attorney, Robert Morgenthau, said of Judge Yates.

Lawyers who have appeared before him say Judge Yates is soft-spoken and never adopts the imperious tone or raised voice favored by some judges. He has a habit of typing on his computer during hearings, which some lawyers say they find distracting.

In recent years, Judge Yates’s willingness to steer cases in the defense’s favor have occasionally gotten him reversed. In one decision that made for memorable tabloid headlines, Judge Yates suppressed evidence of a stolen purse that police had found on a grizzled, unshaven cross dresser. The defendant had attracted the attention of police because, although a man, he was rifling through the purse. Judge Yates threw out the case, ruling that given the man’s “transgender appearance,” police should not have found the purse suspicious. The ruling was overturned by an appeals court.

In another case that drew less newspaper attention but was considered an important ruling at the time, Judge Yates threw out a drug possession arrest that began when police pulled over a driver who neglected to use a turn signal while changing lanes. Judge Yates found that New York law did not require a turn signal to be used during lane changes. An appeals court found differently and allowed prosecutors to proceed with the drug case.

Judge Yates also heard several of the high-profile prosecutions that Mr. Spitzer brought while attorney general.

There is some speculation that Mr. Paterson, who is facing scrutiny over the extent of his expenditures of campaign funds for personal use, may have hired Judge Yates because of the judge’s familiarity with criminal law.

“Maybe the good governor is arming himself with a really competent counsel if the time comes when he has to discuss various campaign funding issues,” a defense lawyer who has appeared before Judge Yates, Martin Adelman, said.

Former colleagues of Judge Yates during his Albany years describe him as a deft dealer with all things legislative.

“This is not a counsel who will come in viewing the Legislature as an enemy but as an institution you have to work with,” Mr. Miller, who is now a lobbyist, said. “And that was the biggest problem with the Spitzer administration — they viewed the Legislature as an enemy.”

Judge Yates spent about a decade as counsel to the Assembly’s codes committee, which handles penal law. Some bills Judge Yates worked on at the time helped prosecutors, including one that it made it more difficult for defendants to claim insanity and seek hospitalization in lieu of prison, Mr. Miller recalled. That initiative, Mr. Miller said, “was not consistent with mine or his philosophy.”

Despite the narrative of his professional career, it’s unclear how much time Judge Yates will spend in his new job on criminal justice policy.

Judge Yates, a graduate of Princeton and Rutgers Law, is known to work long hours and engage in few hobbies, beyond playing an occasional game of tennis or attend an opera performance. A widower, with no children, he lives in SoHo. Although he has sought appointments to the mid-level appellate court as well as the state’s highest court, the Court of Appeals, Judge Yates did not receive higher appointments under the two previous governors. Governor Paterson is expected to get the opportunity to appoint the next chief judge to the Court of Appeals and Judge Yates may find that the being the governor’s counsel positions him well for that job.