UPDATED 11/23/11 1:49 p.m.

CHICAGO (CBS) — A teen has turned himself in to police, after allegedly being seen punching an older homeless man in a startling viral video filmed at the Chicago Avenue Red Line subway stop.

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Scotty Strahan, 18, of the 8600 block of South Normal Avenue, was to appear in bond court Wednesday, charged with two counts of aggravated battery in connection with the attack at the Red Line Chicago subway platform. Information on his bond, or whether a bond was set at all, was not immediately avaialble.

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He turned himself in to Belmont Area detectives, police said.

Police first became aware of the attack earlier in November after the graphic cell phone video surfaced on worldstarhiphop.com, authorities said.

The attack happened in April, the Chicago Tribune reported.

In the video, the older man is shown slowly walking through a crowd in the station, and he appears to be panhandling. Whoever was filming the video follows the attacker as he approaches the man in what appears to be a planned assault.

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The young man follows the homeless man, who is dressed in khaki with a black winter cap and an American flag T-shirt, and taps him on the shoulder.

The attacker and the victim appear to exchange words before the younger man throws a punch with his right hand and cold-cocks the victim. The punch to the victim’s right temple is audible.

The victim then falls backward to the ground, lying motionless.

The last sight in the video is a woman crouching down to help the older man while calling police, and a celebration on a train as it pulls out of the station.

Since the video surfaced, police had been trying to track down both the attacker and the victim, who was reportedly hospitalized after he was struck.

A Chicago Transit Authority spokeswoman said at the time that the transit agency was reviewing security camera footage from the station and would assist police in their investigation.

Earlier this week, Mayor Rahm Emanuel, CTA President Forrest Claypool and police Supt. Garry McCarthy announced that the installation of new security cameras at all 78 ‘L’ and subway stations had been completed six weeks ahead of schedule.

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Police Public Transportation Unit Cmdr. John Graeber said there has been a 40 percent increase in robbery arrests because of cameras installed on CTA train station platforms.