Leslie Crocker Snyder likes to say that she has wanted to put away the bad guys since she was 5 years old. Her earliest memories are of listening at night in her bed to the FBI’s list of most wanted criminals crackling over the radio. Ms. Snyder went on to work in the criminal-justice system, becoming one of the state Supreme Court’s most hard-nosed judges.

She has the death threats to prove it. Even after leaving the bench in 2003 for private practice and some work as a television commentator, and despite the view from some senior law enforcement officials that the threats on her life are no longer serious, Ms. Snyder remains the only judge or former judge in the state to have a round-the-clock security surveillance team provided by the New York Police Department, including an unmarked squad car and a team of plainclothes detectives.

Cops like her. Many officers point to the title of her autobiography, “25 to Life,” named for the most severe sentence a judge in New York can currently hand down.

With fine painted nails, almost platinum blond hair, a knockout wardrobe, and a witty sense of humor, Ms. Snyder has also proved that she is a woman who knows how to get what she wants in a man’s world – even if it means making the trip during her lunch hour from her courtroom in Lower Manhattan to Barneys – “… only a ten-minute cab ride away,” she writes on the first page of “25 to Life.”

Now, after a legal career spanning more than three decades, Ms. Snyder wants to become district attorney. To do so, she is running her first political campaign against arguably the most revered and experienced prosecutor in the country, Robert Morgenthau, whose 30 years of service has been widely praised by both Republicans and Democrats. His lengthy tenure matches that of another legendary prosecutor, Frank Hogan, who served 32 years in the office before dying in the position.

One day, sitting in his office in the Alley that now bears his name, smoking his pipe, Frank Hogan waved a 20-something young lawyer named Leslie Crocker into his office and gave her a job in the Complaint Bureau. Later, Hogan would give Ms. Snyder her coveted assignment to the Homicide Bureau, making her the first female in city history to try murder cases – but only on one condition: She would need a note from her husband. Hogan wasn’t kidding.

“It’s sort of amazing to think of how far we’ve come,” Ms. Snyder, who looks much younger than her 62 years, said one day last week, sipping a cup of tea in a French cafe in Midtown. One of the biggest problems of her campaign, she said, might be that New Yorkers don’t know that the position of district attorney is available in the fall, or that it is an office they can vote on. Her greatest asset could be her guts, she suggested, because over three decades there have been few challengers willing to attack Mr. Morgenthau or his legacy, and she is more than willing to do so, calling his office “stale.” She then proceeded to outline her vision of a more “hands-on” shop, one whose boss won’t turn 90 in four years.

“I think New Yorkers need a new district attorney for a new century with new ideas,” Ms. Snyder said.

Mr. Morgenthau, who turns 86 in July, suffers from poor hearing but is physically in prime condition and mentally razor-sharp as always, friends and colleagues said. He has declined to address Ms. Snyder’s barbs, his campaign, and his age, beyond joking that he is too old to retire.

The fiery former judge may pose the most viable threat yet to Mr. Morgenthau, but critics and political consultants said she faces a long and potentially bumpy path toward the Democratic primary in September. Some question her viability as a candidate and the solidity of her platform. Some question the caliber of her campaign team. Others question her temperament.

While Ms. Snyder called on Mr. Morgenthau last week to dismiss the verdict in a 1990 murder case and demand a new trial for the defendants in light of new evidence, defense attorneys pointed to a case that came before Justice Snyder in 1997, in which she quickly dismissed the results of two fingerprint tests and remanded an innocent man to prison after personally, and wrongly, claiming to identify him using two photographs that were taken 11 years apart.

In that case, according to court documents, prosecutors had mistakenly identified an auto mechanic from Washington Heights as a drug dealer named Ramon Perez, charged on a high-level felony offense and facing the maximum sentence of 25 years to life. While prosecutors offered the judge photographs in which the mechanic and the drug dealer appeared to be the same person, the defense attorney in the case argued that two fingerprint tests, the official basis for identification under the law, had shown the men to be different.

Justice Snyder described the results of the fingerprint tests as “truly absurd,” according to the court transcript, and called the photographs “irrefutable evidence before me that this is the right person.”

“There is not a scintilla of doubt in my mind that this is the person who was arrested and convicted,” she went on to say, according to the transcript. “The photographs look exactly like your client. I will rely upon those photographs.”

There was doubt, however. Additional fingerprint tests were conducted and, again, showed the man in her courtroom not to be Perez, the drug dealer.

Ms. Snyder had no choice but to release the man, Saul Rodriguez, an auto mechanic from Washington Heights, from prison. It was “a nightmare situation” for Mr. Rodriguez, according to his attorney, Kenneth Wasserman, because his client spent three weeks in prison, away from his wife and children, mistakenly identified as another man and facing the prospect of a life in prison.

“This was the classic case of a strong willed judge overly confident in her abilities,” Mr. Wasserman, said, echoing another complaint against Ms. Snyder: that she has always felt more comfortable in the role of prosecutor than an impartial judge, and has attempted to help prosecutors appearing before her bolster their weaker cases.

Asked in her interview with The New York Sun if she had made a mistake in deeming the photographs “irrefutable evidence,” Ms. Snyder said, “Obviously, I did.”

Another explosive issue of the campaign is the matter of rolling back the Rockefeller drug laws, which have recently been rewritten to offer more lenient prison sentences. According to advocates for easing the laws, fully 94% of those sentenced under them have been members of minority groups – groups that constitute a significant proportion of Democratic voters.

Both Mr. Morgenthau and Ms. Snyder have said they are advocates for reform of the Rockefeller drug laws. The questions have now become, who was the first advocate, and who is the more legitimate one.

Ms. Snyder said she was an advocate for reform for nearly the last 10 years. She pointed to an interview she gave on November 12, 1996, for a Human Rights Watch report in which she was quoted, albeit briefly, in supporting rehabilitation efforts. Ms. Snyder also points that she currently sits on the board of directors at Abraham House, a nonprofit institution that aims to provide alternative forms to incarceration.

Mr. Morgenthau said his support of Rockefeller reform has been significantly more visible and goes far deeper in substance. As early as 10 years ago, perhaps earlier, Mr. Morgenthau created an internal policy within the district attorney’s office in which those arrested on a drug charge for the first time aren’t prosecuted under the Rockefeller laws and many nonviolent offenders are given the opportunity to plead down to lesser crimes and be given probation, according to a spokeswoman for the DA, Barbara Thompson.

Leading opponents of the drug laws said that no district attorney in New York has truly spearheaded the movement for Rockefeller reform, but that Ms. Snyder’s track record on the issue is the more suspect, according to the director of the William Moses Kunstler Fund for Racial Justice. That group has been filing court motions on behalf of inmates seeking resentencing and release under the recently revised drug laws.

“When it comes to the Rockefeller drug laws, Leslie Crocker Snyder has not offered one specific program or recommendation of action or policy paper to have these things overturned,” the group’s director, Randy Credico, said.

“She’s looking for an issue, and she should look for another one,” he said. “That dog don’t hunt.”

A supporter of Mr. Morgenthau, Mayor Koch, who elevated Ms. Snyder to the bench in 1983, questioned her motives for running.

“There is no reason for anyone to run against Bob Morgenthau,” the former mayor said. “You need a reason to run. Just because you want the job doesn’t make it a reason.”

Ms. Snyder says she is running because the office needs new blood and a whiff of fresh air, and she thinks she can bring it. But does the tough-nosed judge really think she can end Morgy’s reign?

“I wouldn’t be running if I didn’t think I could win,” she said.

Snyder Fund-Raisers

What do Don King’s attorney, a gruff-talking private gumshoe, and a former U.S. attorney have in common? All are working to raise money for a former Supreme Court judge, Leslie Crocker Snyder, to unseat Robert Morgenthau in the primary race for district attorney this fall.

* Don King’s attorney is Judd Burstein, a former mafia defense lawyer who moved on to defending professional boxers. Among them were a number of pugs with million dollar grievances against King. Mr. Burstein succeeded in netting the biggest civil recovery against King, $7.5 million for Terry Norris, a former middleweight champion who has brain damage. In the trial, Mr. Burstein repeatedly criticized King for masterminding deceitful business practices. Shortly after the trial, Mr. Burstein went to work for King. He has also given a $10,000 donation to Ms. Snyder’s campaign and has acted as her finance chairman, although the campaign has denied that.

* The gruff-talking private gumshoe is Beau Dietl, a retired New York police detective who began courting donors for Ms. Snyder’s campaign until gay and lesbian groups complained his views on the matter were insensitive. Mr. Dietl has been a regular contributor to the Imus radio talk show, and in one session referred to Senator Clinton and the chairman of the Democratic Party, Terry McAuliffe, with terms used to disparage homosexuals. After hearing his comments, Ms. Snyder said she immediately cut Mr. Dietl from her campaign.

* The former U.S. attorney is Mary Jo White of the Southern District, who often clashed with Mr. Morgenthau over jurisdiction and is the honorary chairwoman of Ms. Snyder’s campaign. Of Ms. Snyder, she said, “Leslie has new, very exciting ideas, and she has the education and the courage to carry them out.”