(CNN) -- Police from California's Bay Area Rapid Transit system have begun questioning witnesses to a confrontation that led to a BART police officer shoving an unruly man into a glass window, a top official said Monday.
"We will take our time and we will cover everything that needs to be covered," said Daniel Hartwig, the patrol commander for the BART police force.
Hartwig said detectives have identified and begun interviewing 12 witnesses to the confrontation, which occurred Saturday night at the West Oakland BART station. Based what is known so far, Hartwig said, the officer appears to have acted appropriately.
The incident was captured on video and posted on the Internet, but has since been taken down. Hartwig said investigators have asked the person who posted the video online for his help, but had not received a response.
Police released recordings of 911 calls in which witnesses and a train operator complained that the man arrested, Michael Joseph Gibson, appeared drunk and combative. In a statement issued earlier, BART police said he was "yelling racial slurs and profanity at passengers and challenging customers to fight."
The video showed Gibson being pulled off the train by an officer who put him in an arm grip and forcibly walked him toward the station wall, which is topped by large windows. In the video, the officer forced Gibson against the window, which shattered.
It was unclear exactly what caused the glass to break. The officer sustained facial cuts requiring stitches and a concussion, while Gibson suffered cuts to his hand, forearm, palm and head. The officer was placed on leave due to his injuries, authorities said.
Gibson, 37, of San Leandro, California, is to appear in court Tuesday afternoon, according to jail paperwork. He faces charges of battery on a police officer with injury and resisting arrest -- both felonies -- and public intoxication, a misdemeanor.
He was being held in a jail outside Oakland on Monday evening. He has refused to talk to detectives investigating the case, Hartwig said.
His sister, Lisa Gibson, told CNN on Sunday that her brother was diagnosed with bipolar/schizophrenic disorder and is under a doctor's care. She said he was released from hospitalization earlier this month.
Gibson said her brother appears intoxicated in the video. But she blasted the officer who made the arrest, saying, "Whoever this officer is shouldn't have a job. He has no integrity and a combative mindset."
But Hartwig said police "can't assume this person was mentally unstable."
Saturday's scuffle is the latest incident to draw attention to BART.
Johannes Mehserle, a former BART officer, has been charged with murder in the shooting death of an unarmed man at a transit station on January 1. He faces trial in Los Angeles County, where a judge moved the trial after the shooting -- also caught on video -- prompted widespread media coverage and protests.
CNN's Greg Morrison contributed to this report.