NYPD Officer Kicks Colleague in the Head View Full Caption Rod Risbrook

BROOKLYN — An undercover NYPD officer rushing in to aid uniformed colleagues making an arrest kicked one of them in the head after apparently mistaking him for a suspect, a video obtained by DNAinfo New York shows.

The undercover anti-crime unit officer from the 60th Precinct, whose identity was not released, was stripped of his gun and badge and placed on modified duty after the 90-second clip surfaced, officials said. The incident is now being investigated by the NYPD's Internal Affairs Bureau along with the office of Brooklyn District Attorney Kenneth Thompson, officials say.

The incident in Coney Island's Stillwell Avenue station, which officials say occurred sometime in January, began when two NYPD Transit officers stopped a suspected farebeater.

Officers exchanged words with the suspect and then struggled with him as they began to place him under arrest. Then several other officers from the nearby 60th Precinct rushed into the station via an emergency door — including a burly plainclothes officer dressed in a sweatshirt, jeans and heavy construction boots, according to the video.

The plainclothes officer walked up to the scrum, paused and then reared back with one leg, letting his boot fly into the back of the head of a hat-wearing police officer wrestling with the suspect. The kick had enough force that the sound can be heard on the recording above the din.

"He kicked a cop!” a female eyewitness can be heard saying.

The plainclothes officer then joined the fray, but soon realized his mistake and reached out to rub the back of the head of the officer he kicked, according to the video.

The plainclothes officer then turns to the alleged farebeater and moments later punches him in the face, the video shows.

“You saw that?” the suspect asked bystanders after being handcuffed, referring to the punch, according to the video. An NYPD spokesman declined to identify the suspect because he pleaded guilty to a reduced charge and the case has been sealed.

Throughout the video, officers can be heard repeatedly yelling at the suspect to stop struggling and “give us your hands.”

Rod Risbrook, a professional photographer who shot the video, told “On The Inside" that he was heading home and had just stepped off the train when he saw two officers and the suspect exchanging words.

"He was having a discussion with one of the police," he said. "The next thing I know reinforcements were called in and plainclothes men came out of nowhere."

Risbrook's video, which got more than 1 million views on Google Plus before it was taken down, is the latest videotaped incident of apparent police force to spark an investigation.

It resurfaced following the controversial video showing Staten Island police placing suspect Eric Garner in an apparent "chokehold" July 17. Garner, a 43-year-old asthmatic, later died and the city's Medical Examiner has classified it a homicide.

The NYPD also suspended an officer after he was seen in a video — released by “On The Inside” — punching a 16-year-old who'd been caught with a small amount of marijuana in the face with a gun during an Aug. 29 arrest. His colleague was placed on modified duty after video showed him punching the teen, officials said.

Last month, another officer was suspended after being caught on camera kicking a vendor during an arrest at a street fair in Sunset Park, Brooklyn, police said.

The NYPD's Internal Affairs Bureau also is investigating a video that apparently shows an officer shoving a pregnant woman during an arrest, officials said.

Police Commissioner Bill Bratton recently told a meeting of his top NYPD brass that he was committed to rooting out "bad apples" engaged in brutality and corruption who are tarnishing the successful work the police have done on driving crime to record-low levels.

NYPD officials had no additional comment about the latest video.

Thompson said, “My office is working with Commissioner Bratton to ensure that every member of the community is treated with dignity and respect."