A Bay Area Rapid Transit police officer is facing accusations of brutality after a video showing him pushing an unruly man through a plate-glass window went viral over the weekend.

Police in Oakland, California, have charged Michael Joseph Gibson with felony battery of a police officer, obstructing and resisting an officer, disorderly conduct and public intoxication after a BART officer pulled him off a train at a stop and pushed him into a plate glass window.

Both Gibson and the officer -- whose name has not been released -- were injured in the incident.

Gibson's sister, Lisa Gibson, told CNN that her brother suffers from schizophrenia and bipolar disorder, and had recently been released from hospital. She told the news network she doesn't believe her brother was intoxicated at the time of the incident.

CNN quoted her as saying that the officer in question "shouldn't have a job" because he has "no integrity" and a "combative mindset."

Amateur video of the incident shows Gibson standing and shouting in a train car, before a police officer grabs him and drags him out of the train, moving him against a wall of windows where the officer can be seen pushing what appears to be Gibson's head through a glass plate.

Train riders can be heard applauding as Gibson is pulled off the train, but the applause turns to silence as the officer is seen pushing Gibson through the glass.

One person can be heard to say, "No no, this cop's doing his job, that guy's out of line."

The same person can be heard saying, moments later, "This is awesome!"

For BART, the San Francisco Bay Area's commuter rail system, the incident marks yet another controversy over police brutality inside its transit network. In January, the transit system came under heavy criticism for the shooting death of Oscar Grant, who was shot in the back while lying down on the ground after having been pulled off a BART train on New Year's Day, 2009.

An officer in that case has been charged with murder.

This time, BART was quick to respond to the controversy. As blogger Zennie62 at the San Francisco Chronicle's City Brights blog states, "To BART's credit, it's not sitting on this issue; it responded rapidly, issuing a press statement and holding a press conference within moments."

Bart spokesman Linton Johnson told CNN that it was Gibson's arm, and not his head, that was pushed through the glass, and that the blood that can be seen on the video comes from the officer, not Gibson. The officer is on leave due to his injuries.

This video is from CNN, broadcast Nov. 23, 2009.

Download video via RawReplay.com