Bing Liu, 37, a researcher at the University of Pittsburgh School of Medicine, was found dead Saturday inside a home in Ross Township, north of Pittsburgh, the Allegheny County medical examiner said.

He had been shot in the head and the neck, the agency said.

An hour after Liu’s body was discovered, a second person, Hao Gu, 46, was found dead inside a car less than a mile away, the agency said.

Ross Township police Detective Sgt. Brian Kohlhepp told NBC News that the men knew each other.