NYPD Commissioner James O'Neill is expected to announce his resignation and retirement on Monday afternoon at City Hall. The announcement will take place at 2 p.m., sources told Gothamist/WNYC, and current NYPD Chief of Detectives, Dermot Shea, will replace O'Neill.

“Dermot Shea is a proven change agent, using precision policing to fight crime and build trust between police and communities," Mayor Bill de Blasio said in a statement. "As Chief of Crime Control Strategies and then Chief of Detectives, Dermot was one of the chief architects of the approach that has made New York City the safest big city in America. Dermot is uniquely qualified to serve as our next Police Commissioner and drive down crime rates even further."

O'Neill took over from Commissioner Bill Bratton three years ago, when Bratton left for a lucrative job as a corporate security consultant. ("This job has literally cost me a million dollars a year," Bratton told Charlie Rose at the time, referring to his job as a public servant.)

According to the Daily News, O'Neill is destined for something similar:

The decision by O'Neill follows months of speculation at One Police Plaza that he planned to leave for a job in the private sector and that he was frustrated by what those under him saw as increasingly blurred lines between City Hall and Police Headquarters.

While presiding over a continued decrease in overall crime, O'Neill's NYPD has been grappling with a record-high number of officer suicides. The Commissioner recently fired Daniel Pantaleo, the cop who fatally choked Eric Garner, after an NYPD judge recommended the termination. Rank-and-file cops were not pleased.

"Had I been in Officer Pantaleo's situation I may have made similar mistakes," O'Neill said of Pantaleo's firing. "If I was still a cop, I'd probably be mad at me."

[UPDATE / 2:57 p.m.] At a press conference at City Hall announcing his appointment, Shea said that his deceased father and uncle were both celebrating his new position in heaven.

"There is probably some Irish whiskey being spilled," said Shea, who is the son of Irish immigrants and grew up in Sunnyside, Queens. "Someone between a combination of St. Patrick's Day, the West Indian Day Parade and New Year's Eve rolled in together," Shea said to laughter.

Shea cited his upbringing as the most important factor guiding his decision-making process. "Life lessons—how to treat people, treat people with dignity," Shea said, noting that he spent 20 years as a beat cop in the Bronx after joining the department in 1991.

"There was nothing better than walking out and talking to people," he added.

Asked why he didn't look outside the NYPD for a new commissioner, Mayor de Blasio said that after observing Chief Shea in his role for six years, "I became convinced a long time ago that he was the future of the NYPD." The mayor also downplayed the fact that the NYPD's upper leadership is less diverse than the rank-and-file, and pledged that that too would change.

Mayor de Blasio also batted away calls for Shea's resignation made by victims advocates, who have argued that the NYPD's Special Victims Division is understaffed and ill-equipped to properly handle complaints of sexual assault. A scathing report from the City's Department of Investigation issued last year revealed that the NYPD assigned just 67 investigators to more than 5,000 adult sex crime cases a year, didn't provide its officers with proper trainong, and didn't take cases of acquaintance rape seriously.

"There's a lot of different advocates in the world, and simply being an advocate is not a blanket designation of having a monopoly on the truth," the mayor said. "I think the questions raised about past years were fair. Were there enough personnel? Was there the right kind of approach? I've seen Chief Shea immediately create powerful reforms that were needed," de Blasio added.

Shea pointed to the reforms that have already taken place within the SVD, and said he was planning on meeting with advocates this week: "We hear the advocates. We're not done."

Commissioner O'Neill, who still has a month left on the job, said that the decision to fire Daniel Pantaleo "wasn't a motivating factor" in his resignation. "It wasn't any one factor, it was a lot of things. I'm not getting any younger. I have a family, I have two sons...I have six brothers and sisters I don't see too much," O'Neill said.

"I'm leaving because I have another opportunity," O'Neill added. "It's something I couldn't pass up."

While praising O'Neill's tenure as commissioner, Mayor de Blasio noted that "a real bond developed over the years" between himself and O'Neill. "And this is someone I came to appreciate and respect and enjoy the company of, and I'm gonna miss him," the mayor said.

After an awkward handshake, O'Neill said to laughter, "I'm not hugging you," before the mayor attempted a stiff sideways hug.

"This will be more of the same, and our clients – New Yorkers from communities of color – will continue to suffer more of the same from a police department that prioritizes arrests and summonses above all else,” Tina Luongo, attorney-in-charge of the criminal defense practice at The Legal Aid Society, said in a statement.

Queens City Councilmember Donovan Richards, who chairs the Public Safety Committee, suggested that the mayor should have kept looking for O'Neill's replacement.

"I think there was a missed opportunity here to ensure that the department was reflective of where the department was going, and obviously when you think of the future of New York City and how diverse we are, there was a missed opportunity," Richards said.

"When you talk about other reforms that need to be done around the DNA database, the gang database — and these are items that we’ve worked very closely with Chief Shea on that we did not see as much movement on," Richards added. "So I’m hoping that, you know, perhaps he’s found some new religion on these issues and that we can really push the needle of policing in New York City."

Predictably, Ed Mullins of the Sergeants Benevolent Association was happy about O'Neill's departure (and had nothing to say about Shea).

“This announcement is long overdue. I believe he will go down as the worst Police Commissioner in NYPD history," Mullins said in a statement, calling O'Neill "a puppet of the de Blasio incompetent and dishonest mayoral administration [sic], he has been the catalyst for New York City’s hands-off policing and ongoing descent of overall quality of life and violent street crimes to which we are seeing an increase."