CHICAGO (AP) — Autopsy results show a man slain last month in a Northwestern University professor's high-rise Chicago condo had methamphetamine in his system at the time.

The Cook County medical examiner's office released the findings in Trenton James Cornell-Duranleau's death on Friday. The 26-year-old hairstylist's body was found July 27. He suffered more than 40 stab wounds.

The since-fired Northwestern microbiologist, Wyndham Lathem, and Oxford University financial officer Andrew Warren are charged in Cornell-Duranleau's death.

Authorities have said the attack on Cornell-Duranleau, a Michigan native who had been working in Chicago, was so brutal that the blade of the knife investigators believe was used to stab him was broken.

Investigators say Lathem had a personal relationship with Cornell-Duranleau.

Lathem and Warren surrendered to California authorities Aug. 4 after an eight-day manhunt.