CHICAGO (CBS) ? A woman was injured during a frightening attack and it was all caught on tape. The attacker was an off-duty Chicago police officer who has now been charged. CBS 2 Investigator Dave Savini reports.

Shocking surveillance video shows off-duty Chicago police officer Anthony Abbate, 38, a 12-year veteran of the force, brutally beating a female bartender.

He punches and kicks her.

"He was drunk in a bar. She refused to serve him anymore so he went behind the bar and threw her around like a sack of potatoes," said Attorney Terry Ekl who represents the alleged victim.

The woman was working at Jessie's Shortstop Inn Tavern on the city's northwest side where the alleged assault happened.

Video shot by the tavern in February shows Abbate's attack on the woman, who is half his size, was so violent the bar itself shakes.

Bystanders looked on, but no one stepped in. No one helped the woman until she was back on her feet again.

"The Chicago Police Department made a unilateral decision that they were going to charge him only with a misdemeanor without telling the State's Attorney's Office," said Ekl.

But prosecutors took over and filed felony aggravated battery charges.

"It's one of the most brutal and savage attacks that I have seen caught on tape," said David Navarro, a prosecutor in the case.

Prosecutors are investigating adding possible obstruction of justice and intimidating a witness charges.

"Another individual came in moments after the attack and attempted to offer the victim money in order for her not to prosecute the defendant," Navarro said.

The February attack, caught on the Tavern's surveillance camera, was Abbatte's second assault of the evening, say prosecutors.

"The defendant had attacked another customer earlier that evening. He placed him in a headlock and punched that individual repeatedly," Navarro said.

Abbatte is no stranger to drunken behavior.

He was one of 100 Chicago police officers who had been hired despite having prior drug or alcohol related driving offenses.

Abbate had also been arrested for drag racing and driving on a suspended license.

"Until you told me we did not know he had a prior DUI," Ekl said to CBS 2's Dave Savini.

The night of the attack Chicago police were called, but when they arrived Abbate was long gone.

If convicted, Abbate could get two to five years in prison. His bond was set at $70,000. Abbate has been relieved of his duties and Chicago police are moving to terminate him.

When Savini interviewed him 5 years ago, Abbate said he was sorry for his prior drunk driving and would never do anything like that again. He was also named in a civil rights suit back then. That plaintiff is deceased.

Abbate's attorney would not comment in court Wednesday.