RICH NEGRIN, a former managing director for Philadelphia, on Thursday will become the third candidate to challenge District Attorney Seth Williams in the 2017 Democratic primary.

Negrin said controversies surrounding Williams, who is seeking a third term, were a factor in his decision to join the race.

The Daily News reported in August 2015 that the FBI and IRS, working with a federal grand jury, had subpoenaed financial records from the political-action committee Williams used to seek office in 2005, 2009, and 2013.

Williams in August of this year amended his statements of financial interest for 2010 to 2015, listing $160,050 in previously unreported gifts, including cash, gift cards, $45,000 in home repairs, Eagles sideline passes and airfare and lodging for several vacations.

"Every day, young district attorneys walk into courtrooms cloaked with nothing but the integrity and moral authority of their office," said Negrin, who started his legal career as an assistant district attorney in Philadelphia. "If that's compromised, especially from the top, it's harder for them to do their jobs and seek justice for the city."

Williams, through campaign spokesman Dan Fee, declined to comment.

Fee, in an email, called Negrin's statement "bizarre," adding that assistant district attorneys under Williams head to court "each day with the facts and law on their side."

Negrin's announcement will come just before the start of Pennsylvania Society, an annual weekend event in New York where candidates court political and financial support for their campaigns.

"The great thing is you can do about six weeks of networking in about three days," Negrin said of Pennsylvania Society, where he plans to spread word for forthcoming fund-raisers.

Negrin's campaign released a video Wednesday in which he speaks about communities affected by violence, crime and law-enforcement policies.

Negrin's parents fled Fidel Castro's regime in Cuba in 1961. The video cites the 1979 assassination of Negrin's father in Union City, N.J., by terrorists who mistook him for a communist sympathizer. Negrin, then 13, saw the killing.

In the video, he speaks of being "covered in blood, you know, holding him in my arms as he died."

Heavy with atmospheric scenes of the city, the video shows kids practicing for football games, young families on playgrounds and small-business owners. Negrin said he met the people in the video while working for the city.

Negrin's wife, Karen McRory-Negrin, left her job Friday as assistant chief of the District Attorney's Office's Juvenile Court Unit.

The couple, who live in East Falls, met while working together as prosecutors. Negrin, 50, attended the Rutgers University School of Law and was an assistant district attorney from 1995 to 2000.

He served as managing director during Mayor Michael Nutter's administration from 2010 to 2015. He is now a partner at the law firm Obermayer Rebmann Maxwell & Hippel.

Thomas Leonard, chairman of Negrin's firm, is serving as chairman for his campaign. Leonard has decades of political fund-raising experience for candidates such as former President Bill Clinton and former Gov. Ed Rendell.

Richard Glazer, a lawyer who served on the Philadelphia Board of Ethics with Negrin, will be campaign treasurer. Negrin, with an eye toward Williams' federal woes, said Glazer will "make sure we do everything with the highest standards."

Negrin will become the third Democrat to challenge Williams in the May 16 primary.

Joe Khan, another former district attorney who went on to become an assistant U.S. Attorney in the Philadelphia office, resigned that post in September to become the first candidate in the primary.

Municipal Court Judge Teresa Carr Deni resigned from the bench Friday after 21 years and declared her candidacy Monday.

215-854-5973 @ByChrisBrennan