NEW YORK (AP) - For the second time this year, a New York City police officer has been killed by friendly fire.

Officer Brian Mulkeen was fatally struck by two police bullets while struggling with an armed man after chasing and shooting at him Sunday in the Bronx, Police commissioner James O'Neill said.

"This is an absolute tragedy," O'Neill said Monday, quickly turning the blame on the man Mulkeen was grappling with, who was also killed in the burst of gunfire.

"Make no mistake, we lost the life of a courageous public servant solely due to a violent criminal who put the lives of the police and all the people we serve in jeopardy," O'Neill said.

Investigators are still piecing together exactly what happened, but police officials described a chaotic confrontation in which six officers fired 15 shots in about 10 seconds.

Mulkeen, 33, was on patrol with a plainclothes anti-crime unit when he and his partners encountered Antonio Williams, 27, around 12:30 a.m. Sunday near a public housing complex, police said.

Williams, who was on probation following a drug arrest last year, ran away and officers chased after him.

Mulkeen grabbed him and the two began wrestling.

O'Neill said Mulkeen could be heard on body-worn camera footage saying, "He's reaching for it! He's reaching for it!"

Investigators had previously suggested that Williams had wrested the officer's gun away as the pair struggled. But police said Monday that Mulkeen retained control of his gun and fired five shots after Williams reached toward his waistband, said Deputy Chief Kevin Maloney of the NYPD's Force Investigation Division.

Other officers fired a total of 10 shots.

A loaded .32-caliber revolver belonging to Williams was recovered at the scene, police said. It had not been fired. Police officials said they were still investigating whose shots killed Williams.

"Anybody who wants to play the 'blame the cops' game with this tragedy needs to swallow their rhetoric and look at the facts," said Patrick Lynch, president of Mulkeen's union, the Police Benevolent Association.

"That perp is the one who carried an illegal gun onto our streets. He is the one who chose to fight with the cops. He is solely responsible for our hero brother's death."

Williams previously served 3½ years behind bars for burglary, according to state prison records.

He was due in court in Binghamton on Friday following an arrest in August that stemmed from an alleged physical dispute with a woman. Binghamton Police Department spokesman John Ryan said detectives have provided information about the case to the NYPD.

Court records don't list a lawyer representing him in that matter.

All of the officers except Mulkeen activated their body cameras. He was unable to amid the struggle with Williams, O'Neill said.

"He displayed incredible, incredible courage," O'Neill said.

Mulkeen's death echoed that of Detective Brian Simonsen, who was killed by friendly fire in February.

Simonsen was hit once in the chest by crossfire as he and six other officers fired 42 shots at a robbery suspect who charged toward them and mimicked pulling the trigger of a fake handgun.

MORE: Mourners line highways as fallen NYPD officer is brought home to Monroe 

In more than 6½ years with the NYPD, Mulkeen made 270 arrests - many of them for felonies, including possession of illegal guns.

He left a high-paying finance job to become a police officer because, as friend Daniel Tucker wrote on Facebook, he "felt like he wasn't doing enough with his life."

Mulkeen graduated from Fordham University's business school and worked as a financial adviser at Merrill Lynch in New York from 2007 to 2009, the company said.

In his Facebook post, Tucker recounted Mulkeen's departure from the company. He remembered his friend calling him and saying: "Tuck! I couldn't wait to tell you, I quit my job at Merrill Lynch and I'm gonna be a cop!"

Police officers and firefighters lined up along the New York State Thruway on Monday as a caravan of police vehicles transported Mulkeen's body to a funeral home in his hometown of Monroe, a suburb northwest of the city. His funeral is scheduled for Friday.

Mulkeen, who lived in Yorktown Heights with his girlfriend, an officer in a different Bronx precinct, started his law enforcement career as a dispatcher for the police department in Tuxedo, a town near Monroe. He joined the NYPD in January 2013.

"He brought joy, and caring with him when he came," the Tuxedo Police Department posted on Facebook. "He followed his dream. He will always be one of us, remembered for his courage, his love and his drive. We will never forget, we will always be with you."