​ROCHESTER, N.Y. — ​The man accused of shooting and killing a Rochester police officer is expected back in court Wednesday.

Kelvin Vickers, 21, made his first appearance in Rochester City Court over the weekend. He pleaded not guilty to charges of second-degree murder, assault and weapons possession stemming from the fatal shooting of RPD Officer Anthony Mazurkiewicz.

Officer Mazurkiewicz, a 29-year RPD veteran, was killed after being shot in the upper body. His partner, Officer Sino Seng, an eight-year RPD veteran, was shot in the lower body and treated at Rochester General Hospital. He has since been released. 

Police say Mazurkiewicz was working with Officer Seng in an undercover police van on Bauman Street Thursday, when, they say, Vickers ambushed the officers, firing at least 17 rounds into the vans. 

Vickers was found an hour later in a vacant house nearby, and police said a loaded handgun was found that may have been used in the shooting.

A third person, identified by police as a 15-year-old girl, was also wounded.