ROCHESTER, N.Y. (AP) — The suspect in the killing of an upstate New York police officer in July was released from prison two months earlier, and could face a life sentence without parole based on new charges a prosecutor announced Wednesday.

Kelvin Vickers, 21, is charged in an eight-count indictment with aggravated murder, attempted murder, assault and weapons counts for the July 21 attack that killed Rochester Police Officer Anthony Mazurkiewicz, 54, and wounded Officer Sino Seng as the two sat in an unmarked vehicle. A funeral for the fallen officer was held Monday.

Investigators said the shooter, unprovoked, approached from behind and fired at least 17 rounds, including one that penetrated a nearby house and injured a 15-year-old girl inside.

Vickers, who is from Boston, has a long criminal record dating to when he was 12 years old and accused of assault and battery on a police officer, said Monroe County District Attorney Sandra Doorley.

At a news conference with other officials Wednesday, Doorley said Vickers’ juvenile record includes burglary, strangulation with a deadly weapon, assault with a deadly weapon, and two firearms offenses. As an adult, he served a prison sentence of 2 1/2 to 3 years for unlicensed weapons possession and was released by the Massachusetts Department of Corrections on May 24.

The aggravated murder charge carries with it a mandatory life sentence without the possibility of parole. It is supported by evidence suggesting the shooter knew or should have known that Mazurkiewicz and Seng were police officers, Doorley said.

She declined to discuss a possible motive for the July attack. Authorities have said the two officers were part of a plainclothes unit and were investigating a murder.

“This is not only a nightmare for (police) and the Mazurkiewicz family, it’s a nightmare for our city,” Mayor Malik Evans said at the news conference.

The killing happened on the same day that Evans declared a state of emergency over gun violence in the mid-sized city.

An hour after the shooting, Vickers was found in a nearby vacant house. He pleaded not guilty to initial charges of second-degree murder, attempted murder, assault and weapons counts and has been held without bail.

“He was not a Rochester resident. He was just released from prison. He was here and now he’s accused of killing a police officer,” Doorley said.

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