Cop Punches Woman: Bus Passenger Tapes LA Sheriff's Deputy Hitting Rider (SHOCKING VIDEO)

A passenger on a bus recorded a Los Angeles cop punching a woman in the face who apparently hadn't been violent while the camera rolled.

Jermaine Green, the man who taped the Monday night incident in Bellflower, told NBC LA that the Los Angeles County Sheriff's deputy who struck the woman threatened to arrest him if he didn't hand over his camera phone.

The woman brought a stroller laden with pillows on to the bus and Green described her as having "special needs." Two deputies allegedly boarded the bus at the next stop and confronted the lady, who began cursing at them, according to Green's retelling.

His video begins with the woman standing in the aisle and cursing repeatedly. One of the deputies, a woman, grabs her arm.

The audio is unclear, but the woman appears to try to walk past the deputies. The male deputy, who had been holding her wrists, cocks his right arm and throws a right-handed punch that knocks the woman off balance.

The arguing continues as the woman is restrained on a seat. The tape cuts out after more deputies board the bus.

A spokesman for the sheriff's office told LA Weekly that the police accosted the woman, because they'd received a report that said she "almost attacked an elderly man."

The woman, whose name was not given, has previous arrests, including charges of assaulting a police officer, the spokesman said. He added she had acted aggressively towards the deputies.

The spokesman's statement said the woman had "mental challenges."

Officials from Internal Affairs and the Office of Independent Review will investigate, LA Weekly reports.