A man claiming to be an off-duty Chicago PD officer pinned a 14-year-old boy to the ground with his knee after accusing him of stealing his own son's bike -- and the whole thing was caught on video.
The boy's parents tell TMZ the incident happened Friday at a Starbucks in Park Ridge, IL -- just outside of Chicago. They say their son, who is Puerto Rican and an honor student, athlete and member of the local church was at the coffee spot with a group of friends and saw an abandoned bike laying on the sidewalk.
You can see in the video, the situation is tense, with the other teens coming to their friend's defense ... eventually pulling him away from the man.
A spokesperson for the Park Ridge PD tells us the man told their officers, who responded to the scene, that he was an off-duty Chicago Police officer. We spoke to a rep for The Chicago Police Department who tells us they're conducting an internal investigation into the situation.
The 14-year-old's parents are pissed -- pointing out their son was the only kid in the group who was of a different ethnicity ... and have plans to file a formal complaint in the near future.
Park Ridge is currently investigating the incident ... and tell us at this time, no arrests have been made.