Larry Krasner took a deep breath and paused before answering the question. How was he different from the six other progressive-leaning Democrats running for district attorney?

"There are words and then there are things not made of air," Krasner told a crowd recently at  Arch Street United Methodist Church. He then took aim at the other candidates, five of whom have worked in the District Attorney's Office and a sixth who was a judge for 21 years.

"All these other candidates have been a part of the problem," he said. "They have done nothing to change the problem, but now all of a sudden in this race, when the popular view on criminal justice has shifted ... they're the biggest reformers you've ever seen."

Krasner, 56, has tried to differentiate himself as the true progressive in the May 16 Democratic primary. For those who doubt that, he points to his record. For 30 years he has worked as a criminal defense attorney specializing in civil rights. He has earned renown representing activists and protesters, including 400 people arrested during the 2000 Republican National Convention, AIDS activists, and members of Black Lives Matter.

Through his work, Krasner has attracted the support of a political action committee linked to billionaire George Soros, who has backed progressive Democratic candidates nationwide. The PAC, Safety and Justice, has spent $600,000 on television and radio ads supporting Krasner.

"Everybody's got to play by the same [campaign finance] rules," Krasner said when asked earlier about the possibility of getting Soros' backing in the race. "I don't see why liberals and progressives would sit on the sidelines and let big money, which is overwhelmingly conservative, decimate democracy without responding to it to the best of their ability in the same fashion."

Krasner says that if he is elected, the DA's Office will no longer seek the death penalty in capital murder cases. That would represent a sea change. When Lynne M. Abraham was at the helm, she was labeled "the deadliest DA" by the New York Times for the frequency with which she sought capital punishment. Krasner says little has changed, and describes the office in unapologetically harsh terms.

"I have seen, in essence, a system that has completely run off the rails," Krasner said. "A place with a mad zeal for the highest charge, for the highest level of conviction, a culture that can find no flaw in police misconduct, that is drunk on the death penalty. It's like watching a car crash in slow motion for 30 years."

Krasner says he inherited idealism and sense of justice from his parents. His father, a crime-fiction author, was the son of Russian Jewish immigrants, and his mother was an evangelical Christian minister.

He grew up in St. Louis, and attended the University of Chicago and then Stanford Law School. He worked as a federal public defender in Philadelphia for about six years before opening his own private practice, Krasner & Long LLC, in 1993. He has been married to Lisa M. Rau, a judge on the Court of Common Pleas, for 27 years.

In 1990, Mayor W. Wilson Goode appointed Krasner to a committee investigating a conflict between AIDS activists and Philadelphia police in front of the Bellevue hotel, which left several protesters beaten and bloody. After the Republican convention in 2000, Krasner was part of a team of lawyers who took on the defense work of about 400 protesters arrested. Nearly all of the defendants were acquitted.

"I think my biggest accomplishment has been just to represent underdogs," Krasner said. "To represent Philadelphians, one person at a time, when they didn't have a lot of money and they weren't well-connected and they weren't famous and they weren't rich."

One of his higher-profile clients was former Eagles running back LeSean McCoy, who was involved in a nightclub brawl involving off-duty police officers. Charges were never filed against McCoy.

Krasner says his defense work doesn't make him soft on crime, but rather someone who can differentiate between redeemable defendants and hardened criminals.

"I think the DA's Office, they treat the good guys worse than they need to and sometimes they don't treat the bad guys badly enough," he said. "When you've actually been a criminal defense attorney, you've talked to people, you understand it in three dimensions. It makes it easier."

Krasner has sued law enforcement or the government more than 75 times on behalf of clients. He represented 60 people suing the city and six narcotics officers charged in a federal corruption case. The officers were acquitted in May 2015, but dozens of the convictions they'd worked on while on the beat were overturned.

Krasner dismisses any concern that his concentration on police misconduct cases would make it difficult for him to work with officers if he were elected DA.

"I think good cops love me because they don't like cops who lie, cheat, and steal," he said. "I think bad cops don't love me because they like to lie, cheat, and steal."

Krasner's law office, a two-story building on narrow Camac Street in Center City, has become a gathering place for civil rights leaders in the city. Lawyers and activists gathered for a "know-your-rights" meeting ahead of the Democratic National Convention last year. Krasner sees his activism as a trait the city's district attorney should have.

"It's not just the role of the prosecutor to prosecute," he said. "It's also the role of the prosecutor to advocate and lobby for appropriate legislation and appropriate regulation."

Krasner's civil rights work has resulted in some key endorsements in the black community. He recently won the endorsement of a coalition of politically influential African American ward leaders in the city's Northwest.

He also got the backing of AFSCME District 1199C, a union representing health-care workers, many of them African American. Michael Coard, a prominent attorney and writer in Philadelphia, described Krasner as "the blackest white DA candidate ever" in a column in the Philadelphia Tribune.

At the church event last month, a woman introduced Krasner as "a reincarnation of the late, great attorney Johnnie Cochran," the criminal defense attorney who represented O.J. Simpson.

Before the event ended, Krasner summed up the reason he's running for the job.

"I just hate bullies," he said. "I hate bullies when they're on the street corner beating up on Grandma. I hate bullies when they're little kids. And I hate bullies when they happen to have a uniform on."