WAUKEGAN (AP) — The Lake County coroner has determined that the death of a suburban Chicago teenager at the hands of Zion police officer was a homicide.

Lake County Coroner Thomas Rudd on Tuesday released autopsy reports that showed 17-year-old Justus Howell of Waukegan had small amounts of alcohol and marijuana in his body when he was killed. Howell was shot twice in the back by a nine-year police veteran after a foot chase.

Police say Howell was involved in a scuffle while trying to steal a handgun during a street sale just before the officer shot him.

State’s Attorney Michael Nerheim says a homicide is defined as the killing of a human by another human and is not necessarily murder. He said an investigation continues to determine whether the April 4 shooting of Howell was a “justifiable homicide.”