BUFFALO, N.Y. (AP) — The state Attorney General's Office is investigating the fatal shooting of a western New York man by a police officer.

Attorney General Eric Schneiderman announced Tuesday that he has opened an investigation into an altercation Sunday that left 26-year-old Jose Hernandez-Rossy dead and Buffalo Officer Joseph Acquino with a head wound.

Police officials say Acquino and his partner had stopped Hernandez-Rossy's vehicle for a traffic violation. Authorities say Hernandez-Rossy struggled with the officers and shot Acquino in the ear.

Police say Acquino's partner then fatally shot Hernandez-Rossy, whose gun hasn't been found. Witnesses have said he wasn't armed.

A 2015 state law allows the attorney general to act as a special prosecutor when unarmed civilians are shot by law enforcement officers.

Buffalo police say they're cooperating with the state investigation.

More From WIBX 950