A 60-year-old man was killed in a shooting Saturday on the South Side, police said.

Donald Ruben was walking in an alley just after midnight in the 9500 block of South University Avenue when he was shot in the head, Chicago police and the Cook County medical examiner’s office said. Ruben was taken to the University of Chicago Medical Center where he was pronounced dead a short time later.

An autopsy conducted Sunday said he died of a gunshot wound to the head. The medical examiner’s office ruled his death a homicide.

A witness told detectives they saw an unknown number of people running down the alley after the shooting, police said.

No arrests have been reported. Area South detectives are investigating.

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