The man was walking into a gas station just before 9:30 p.m. in the 3300-block of West Harrison Street in the city's Homan Square neighborhood, when he heard gunshots and felt pain, police said.
He had been shot in the lower back, according to CPD.
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Chicago fire crews treated him on the scene, and he was taken to Mt. Sinai Hospital in serious condition, police said.
No one was in custody Tuesday morning, and Area Four detectives are investigating.
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