New Video Shows Teen Slammed by Guard, Beaten by Inmates in Rikers Island Jail The teen spent 3 years in Rikers after cops accused him of stealing a backpack.

 -- Newly released surveillance footage from Rikers Island, New York City's 400-plus-acre prison complex, is raising concerns about alleged abuse and violence inmates face while behind bars there.

The footage, obtained by The New Yorker, appears to show New York City teen Kalief Browder being slammed to the ground by a Rikers Island guard in one incident and then being beaten by other inmates in another.

Browder, who turns 22 next month, spent three years at Rikers Island -- two years in solitary confinement -- while waiting for a trial over police accusing him of stealing a backpack in May 2010. Browder was released in June 2013 when the charges against him were dismissed.

In an interview last July, Browder told ABC News that he was held there for three years because his mother could not afford to pay his bail, set at $3,500, and a trial kept getting delayed.

"Only thing on my mind was that I gotta go home, I didn't do this," said Browder, who was 16 when he was first incarcerated at Rikers. "Now I'm in jail around these grown men and they're, you know, they're fighting each other. I don't know. It was like hell on Earth."

Browder said he was beaten, stomped on and hit with weapons by correction officers.

"They cuffed me to the back, and they were just beating on me while I was in the cell," he said.

In the newly released security video, reportedly from Sept. 23, 2012, a guard can be seen arriving at Browder's cell to escort Browder to the shower, The New Yorker reported.

After a few seconds, the guard appears to slam Browder, who is handcuffed, to the ground and then hold him down. Two more guards appear to run up to the guard and Browder.

The video is then followed by footage, reportedly from Oct. 20, 2010, after Browder punched a gang leader at Rikers who spat on him, according to The New Yorker. Browder was then beaten, the magazine reported.

A group of inmates can be seen on the video attacking Browder, who appears to be punched kicked to the ground. Two guards then appear in the video, and they seem to try unsuccessfully to stop the fight. After some time, the video shows Browder being put into another room, where he is seen walking around with his hands to his head.

After a few minutes, another inmate can be seen kicking in the door to the room Browder is isolated in, and the group is seen trying to beat him again. At the end of the footage, guards finally get the inmates out, and Browder kneels on the floor, facing the wall with his hands behind him, as armored officers walk in.

A spokesperson for the New York City Department of Correction said the agency's commissioner is very troubled by what he saw on the footage of the guard apparently slamming Browder in 2012.

"He and Mayor [Bill] de Blasio have already adopted a 14-point anti-violence initiative to change the culture at DOC, and changes to the DOC’s Use of Force policy are already under way," the spokesperson said. "Training curricula for officers will be revised to reflect these changes. The Department is re-training the officer involved."

Browder's lawyer, Paul Prestia, told ABC News today that a lawsuit against the city is pending, but was unable to immediately give additional information.

A spokesperson for the New York City Department of Law told ABC News today, "Mr. Browder's suit is currently under review."