Police are investigating a robbery and subsequent attack that took place on the CTA Blue Line at the Oak Park Avenue stop at 1 a.m. on Feb. 19.
The victim, a Chicago man, fell asleep on the eastbound train when several teenagers took his backpack, which contained $700, medication, clothing and an LG cellphone.
The victim struggled to retrieve his backpack, when one of the teenagers approached from behind and punched him in the head several times.
The offenders fled the train toward the East Avenue exit.
The estimated loss is $1,550.