Police said the robbery happened around 3:30 a.m. on Monday, Dec. 15 near West 79th Street and South Perry Avenue in the city's Greater Grand Crossing neighborhood.
The suspects were on a CTA Red Line train when they targeted a passenger, police said.
CPD provided photos of all seven suspects, who they describe as males of unknown ages.
Police asked anyone with information to call them at 312-745-4447 or submit an anonymous tip at CPDTIP.com and use reference #JJ524516.
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