Police looking for suspects after video of Chicago subway attack released

(CBS/WBBM) CHICAGO - Investigators are using video that has just recently surfaced on the Internet to try to solve an assault at a Chicago subway station platform.

The video, posted at worldstarhiphop.com, shows a young man and an older man exchanging words at the Chicago Avenue Red Line Station.

Then the younger man is seen throwing punch and the older man falls backward to the ground. He then gets on a train and begins laughing about the assault with friends, as a woman on the platform went to the man's aid.

The assault is believed to have happened in April.

CBS station WBBM reports that police are still trying to find the people involved.