Austin, TX -- Law enforcement officials are investigating one of their own -- union president Ken Casaday -- after a video surfaced showing him punching a suspect in the back of the head for having touched another police officer's horse.

Activists with the cop-watch group Peaceful Streets uploaded the video on YouTube. In it, Casaday is shown sucker-punching a suspect who was already being restrained by four other policemen during routine patrol along 6th Street near Trinity Street in the early morning hours of June 18. The officers reportedly were trying to clear the street of revelers to clear the roadway as they typically do at around closing time at the bar-lined corridor frequented by a largely young crowd. The officer on the horse doesn't seem receptive to having one 6th Street patron touch his horse.

The video then shows four officers restraining the horse-admiring reveler for having touched the equine anyway, with Casaday emerging from the left of the screen to punch the crouched man in the back of the head. The horse-petting suspect was already restrained by the other officers when Casaday approached to deliver the punch, the video shows.



According to an arrest affidavit cited by the Austin American-Statesman, an officer was prepared to place the man under arrest for "interference with a police service animal," the officer wrote. Casaday didn't return calls from the Statesman seeking comment. The newspaper also reports that Casaday hasn't been placed on administrative leave pending the outcome of the internal investigation.

As head of the police union, Casaday is arguably the most vocal critic of Austin Police Department Chief Art Acevedo as it relates to any disciplinary actions police brass sometimes have to take against other officers found to have violated department policies.

Recently, he took Acevedo to task for having fired police officer Geoffrey Freeman, who shot dead an unarmed black teenager who was found running through the streets of his neighborhood naked. He's vowed to fight in getting the fired officer's job back.

Ironically, Casaday last year complained to a television station of what he termed the YouTube "gotcha culture," which he said unfairly portrays police officers in performing their patrol duties during tense-filled encounters with members of the public. "6th Street has always been a powder keg waiting to happen," Casaday told KEYE-TV in November. "Any use of force, no matter how minor it is, it just looks bad. Any time you have to physically put your hands on someone you can't make it look good."