Shocking video shows a group of 11 teens attacking a 68-year-old man on a Chicago train after one of them tried to rob him while he slept.

Security camera footage shows the man sitting on the train and sleeping as a group of teens make their way through the train car.

One of the girls stops and can be seen trying to go through the sleeping man’s pockets. The man eventually wakes up and the two get into a scuffle.

The brutal beating of the 68-year-old man by 11 teens on a CTA train was captured in a disturbing, graphic video obtained by Fox News.

Watch the video:

The Chicago Police Department said the beating is under investigation, but no one is in custody because the victim “was unable to identify his attacker(s) due to his injuries.” A police source said that the Cook County State’s Attorney’s Office “wouldn’t touch” the case if the victim can’t identify those accused or is unable to cooperate.

When reached about prosecuting the case, state’s attorney’s office responded: “We are unable to comment.”

The footage shows one of the female teens first trying to pickpocket the victim while he’s asleep. The man awakens, tries to fend off the teens, but the woman drags and beats the man.

She then appears to run to another car, and returns with a group of teens including five men and two women. They surround the man seated on the train.

One man pummels the victim, even lifting himself up on the train’s bars to repeatedly kick him in the upper body and face.

The video also appears to show many bystanders failing to intervene.

Police documents indicate the 68-year-old man was left to bleed on Chicago’s red line train. Train workers helped the man off at the Argyle station and authorities were able to interview him.

He told police he fell asleep, then woke up to a group of teens surrounding him trying to pickpocket him. The victim said he told them, “don’t even think about it.” The victim said he feared for his safety and swung at one of the teens, but missed then was beaten with “closed fists and foot strikes.”

He was rushed to the hospital and treated for lacerations to the head and body soreness. Police documents indicate he suffered blunt force trauma.

Police later picked up a group of teens near the Argyle train station, detained them and took reports. The teens were returned home.

The Argyle station is on Chicago’s north side in the Uptown neighborhood, which is a few city blocks west of Chicago’s famed Montrose Beach. The station is nestled between notable nearby communities like Andersonville and Wrigleyville.

The Chicago Police Department has not made any arrest in connection the beating as the victim ‘was unable to identify his attackers due to his injuries.’

A single witness is listed on the police report.