CHICAGO (AP) — Defense attorneys for a white Chicago police officer charged with murder in the shooting of black teenager Laquan McDonald are raising questions about the thoroughness of the autopsy.

Forensic pathologist Shaku Teas was the first witness called as Jason Van Dyke’s lawyers began presenting the defense case on Monday. Van Dyke shot McDonald 16 times.

Cook County’s chief medical examiner testified last week that it’s impossible to determine the exact order of the wounds.

But Teas testified that a shot to McDonald’s neck was the first or second shot. She says it was fired when he was still standing.

She believes the fourth shot hit McDonald’s right chest and caused him to die rapidly. She says the wound was consistent with McDonald being turned toward the officer when he was shot.

Video shows Van Dyke continued to fire at McDonald after the 17-year-old feel to the ground.