San Antonio police are investigating the death of a homeless man whose body was found behind a barber shop on the city's Southwest side.

The man's body was found stabbed to death behind a barber shop in the 300 block of Valley Hi, near Loop 410 south of Highway 90.

Police said the barber shop's owners allowed the man -- identified as 57-year-old Alfredo Barrera -- to stay in a makeshift structure behind the shop.

He was found by a passerby Tuesday morning with multiple stab wounds to his chest and stomach.