New York City Police Commissioner James O'Neill has resigned, Mayor Bill de Blasio said Monday.
O'Neill plans to take a job in the private sector.
"I came into this job with one mission: to fight crime and keep everybody safe, and we did it and continue to do it," O'Neill said during a press conference Monday.
The mayor said O'Neill was the "architect of neighborhood policing. He drove crime to record lows while working tirelessly to bring police and communities together. He leaves behind a city that's safer than it's been in decades," de Blasio tweeted. "I'm lucky to have worked with as good a man as Jimmy O'Neill."
De Blasio introduced a successor, Dermot Shea, who served under O'Neill as Chief of Detectives.
"Dermot is one of the best prepared incoming police commissioners this city has ever seen," the mayor said at the press conference.
"Born and raised in Sunnyside, Dermot Shea is a New Yorker through and through," de Blasio tweeted. "A 28-year veteran, he knows what it's like to walk a beat and lead a precinct. He helped build the strategies that have driven crime to record lows. He's a proven change agent. As Commissioner, Chief Shea will focus on putting 21st century precision policing to work in order to deepen police-community bonds and end the scourge of gun and gang violence."
De Blasio focused on Shea's experience and roots in introducing the leader of a department that has had a strained relationship with minority communities, especially since the death in custody of Eric Garner.
Shea, who has served the force in varying roles for 28 years, is the son of Irish immigrants, growing up in Queens with four siblings in a one-bedroom apartment.
"Treat people with dignity, respect, treat people the same," Shea said in speaking of values instilled in him by his mother.
"We cannot and will not rest until all New Yorkers feel safe," he said.
O'Neill's first day on the job coincided with the bombing on W 23rd Street in Chelsea and his tenure included two other terror attacks.
He paid tribute to the families of officers who died in the line of duty during his time with NYPD.
"This is not an easy job, the job of police officers," he said.
O'Neill oversaw a continued drop in crime and arrests. He also faced criticism from within his department after he terminated the officer, Daniel Pantaleo, who put Garner into an unauthorized chokehold that contributed to his death.
"This is a safer city and fairer city," said Mayor de Blasio in crediting O'Neill for transforming the police department to one focused on neighborhood policing that brought officers closer to the communities they serve.
New York City police commissioner resigns, de Blasio announces new chief