This is the race Rich Negrin says he always wanted to run.

He just didn't expect this to be the time for him to run it.

Negrin is one of seven Democrats seeking their party's nomination in the May 16 primary election for district attorney.

He spent five years as a prosecutor in the city, but is much better known for his six years as Philadelphia's managing director under former Mayor Michael A. Nutter.

Negrin was always seen as ambitious. People came calling with ideas for public office.

"I don't want to be the mayor of the city of Philadelphia," Negrin said. "I don't want to be a governor. I don't want to be a senator. I don't want to be anything else. I want to be the district attorney of the city of Philadelphia. That's who I am."

Negrin, speaking in a conference room of the law firm where he is now senior counsel, with a 33rd-floor view over City Hall, said the legal mess that has upended the career of District Attorney Seth Williams pushed him to run earlier than he expected.

After all, he had only been back in the private sector for 16 months.

"This is something I would have thought about doing later, not so soon after leaving public service," Negrin said. "But I couldn't watch an office that I love and have a passion for just be demoralized and destroyed in the public eye."

Negrin in December became the third Democrat in the race. Williams dropped his bid for a third term in February and was indicted in March on 23 counts, accused by a federal grand jury of accepting bribes from two businessmen and stealing money meant for the care of his elderly mother.

Negrin's path to this campaign started in 1979, when he was 13 and his father arrived to drive him to a Pop Warner football game.

Negrin's parents had fled Fidel Castro's regime in Cuba in 1961. His father later helped negotiate the release of political prisoners in that country.

Two men from an anti-Castro terrorist group, Omega 7, drove by wearing ski masks and gunned down Negrin's father in front of him.

Negrin said the first lawyer he ever met, while he was testifying five years later in the federal trial of Omega 7's leader, was the federal prosecutor who won a conviction in that case.

"In many ways for me, that most horrific experience was what piqued my interest and steered me toward law," said Negrin, who started his career in the District Attorney's Office after graduating from the Rutgers University School of Law. "I had a great experience there. Besides managing director, that's the best job I ever had. I love that office. That's where I met my wife."

Negrin's wife, Karen McRory-Negrin, left her job as assistant chief of the District Attorney's Office's Juvenile Court Unit in December, a week before he entered the race.

Negrin cites the availability on the internet today of the same model of gun used to kill his father for why he served on the board of CeaseFirePA, an anti-gun violence group.

On the campaign trail, Negrin has been touting his support from law enforcement groups, including an endorsement from Fraternal Order of Police Lodge 5, which had been advocating to oust Williams from office before he dropped out of the race.

He also had a bit of political luck in mid-March, when ballot positions were drawn for the seven candidates. Negrin will be listed first on the ballot, which tends to be advantageous in low-turnout elections when voters may not have been as tuned in about the campaigns.

Negrin falls in the middle of the pack of candidates in years of experience as prosecutor. Two have more experience while two have never worked as prosecutors.

The District Attorney's Office has about 560 employees and a projected budget of $54 million for the fiscal year that starts July 1, including $37.8 million from the city's General Fund and $16.2 million from the Grants Revenue Fund.

Negrin has been stressing his experience as an administrator in campaign forums.

"This is no time for on-the-job training," he told a forum this week sponsored by the Greater Philadelphia Chamber of Commerce.

Nutter opted to shift some of the power typically held by the Managing Director's Office to deputy mayors. Negrin said Nutter wanted the managing director, acting like a chief operating officer for the city, to focus on the "the significant internal infrastructure" of administrative departments.

That left him to oversee departments that handled technology, fleet management, human resources, special events, the 311 system, procurement, public property, records, and Philly Rising, a program that targeted neighborhoods in the city dealing with crime as a chronic problem.

He described those as the "internal nuts and bolts departments" that "touch every other department that you need to run a city."

Like his six opponents, Negrin has been talking a lot about reforming the city's criminal justice system -- ending cash bail for nonviolent offenders, seeking treatment instead of prosecution for people with drug addiction, and community re-entry programs for inmates being released from prison.

Negrin pitches himself as the candidate who can take ideas about reform and make them reality.

"It's the rare combination of prosecutorial experience, credibility with all the stakeholders, whether it's police, city government, communities -- I'm the only one that has that," Negrin said.

The District Attorney's Office, mired in scandal, with a leader who refuses to resign despite a looming federal trial, is ripe for reform. Not that it will come easy.

"Managing cultural change in a large organization is incredibly hard," Negrin said. "Doing that in government is even harder."