CHICAGO (CBS) — Chicago police have released surveillance camera video of a man suspected of posing as an undercover police officer before punching and robbing a 70-year-old man at a Blue Line subway station in the Loop.

The video shows the suspect boarding a CTA train at the Clark/Lake stop on the Blue Line about five minutes before he allegedly robbed a 70-year-old man on the platform at the Monroe stop.

Police said the suspect approached the victim around 2:45 a.m. Tuesday at the Monroe stop, claimed he was an undercover police officer, and demanded the man’s ID.

blue line robbery 1 CPD Releases Video Of CTA Robber Who Posed As Undercover Police Officer

Surveillance camera images of a robber who posed as an undercover police officer, punched a man in the face, and stole his wallet at the Monroe stop on the CTA Blue Line on March 6, 2018. (Credit: Chicago Police)

When the victim pulled out his wallet, the robber tried to snatch it. When the 70-year-old man resisted, the suspect punched him in the eye, and ran off with his wallet.

The victim was taken to Northwestern Memorial Hospital for minor injuries.

Police said the robber was a black man who appeared to be a 50 to 55 years old, 6 feet to 6 feet 2 inches tall, and 180 to 220 pounds. He was last seen wearing a grey knit cap, black puffy coat, blue jeans, and tan boots. He also was carrying a black garment bag.

cta robber CPD Releases Video Of CTA Robber Who Posed As Undercover Police Officer

Surveillance images of a man suspected of robbing a 70-year-old man at the Monroe station on the CTA Blue Line on March 6, 2018. (Credit: Chicago Police)

Video of the suspect appears to show white patches of skin on his hands, possibly from a condition known as vitiligo.

Anyone with information about the robbery should call Area Central detectives at 312-747-8384, or submit an anonymous tip to tipsoft.com.

blue line robbery 2 CPD Releases Video Of CTA Robber Who Posed As Undercover Police Officer

Surveillance camera images of a robber who posed as an undercover police officer, punched a man in the face, and stole his wallet at the Monroe stop on the CTA Blue Line on March 6, 2018. (Credit: Chicago Police)

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