Transit police in San Francisco face a lawsuit claiming they used excessive force on a drunken woman last year.

The woman claims newly released video of the incident shows officers violently knocking her to the ground for no reason. The encounter allegedly left her with broken bones, reports CBS News correspondent Ben Tracy.

In the new video, Megan Sheehan can be seen waiting for a train after a night of heavy drinking when Bay Area Rapid Transit police officers arrested her.

"I was so embarrassed when I saw the videos. I can't believe what I was saying. I was just so belligerent and foolish," Sheehan said.

Despite her behavior, she said, nothing she did justifies what happened next at the Santa Rita jail.

"Don't touch me like that!" Sheehan can be heard saying in the video. Then she hit the floor.

In his police report, the officer said Sheehan "suddenly turned towards me and began violently punching with a closed fist at my face." He went on: "To protect myself from her attack ... I used an arm-bar take-down and guided her to the ground."

But Sheehan and her attorneys said footage from surveillance and police body cameras tells another story.

"We don't see Megan Sheehan trying to punch the officer several times in the face," her attorney Lizabeth de Vries said. "We don't see her doing anything that would cause any officer to believe she was an imminent threat that requires this kind of force. ... What we see is, without any of this happening, two officers held back Megan Sheehan's arms and threw her face first to the ground."

"I had a gash above my left eye, I had a few stitches there, I had four broken bones around my orbital socket, and stitches in my lip, and they knocked out a tooth and chipped another one," Sheehan said.

Sheehan filed a federal civil rights lawsuit claiming officers used excessive and unreasonable force.

"Whether they thought she was so belligerent and so drunk that she had it coming -- I don't know," de Vries said.

"I was already arrested, I was already in custody, there was police all around and I don't know why they had to use that much force," Sheehan said.

A spokeswoman for BART said the agency would not comment because of the pending litigation.