CHICAGO (CBS) — Three suspects are in custody Monday after beating and robbing a man on Sunday night, who was waiting for a CTA train near the Illinois Institute of Technology campus.

Police say a 19-year-old man was at the 35th Street Green Line stop around 8 p.m. Sunday night when three people approached and asked the victim for money. When the victim declined, the offenders struck the victim several times. The offenders robbed the victim of his cell phone, demanded that the victim give them the password and then fled the scene.

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The 19-year-old man declined medical treatment.

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Illinois Institute of Technology Public Safety Officers were able to locate and detain the three offenders.

CBS 2 spoke to CTA passengers who were surprised by the attack, especially because police headquarters are close by.

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The three offenders were all 17-years old. They were taken into custody and charged. One was charged with felony robbery and misdemeanor battery. The other two were charged with felony robbery.