WATCH: Mesa Police Officers Brutally Beating Robert Johnson

YouTubeBody cam footage of Mesa police repeatedly punching and kicking unarmed Robert Johnson.

The Mesa Police Department in Arizona released disturbing body cam footage showing a group of Mesa officers brutally beating an unarmed man while he sat peacefully against a wall and cooperated with police.

The 20-minute video, taken from a surveillance camera, shows several police officers kicking and punching Robert Johnson. At one point, they slam his head into an elevator door.

According to Vox, the incident took place on May 23 after officers responded to a 911 call from a local apartment complex. “They arrived to find Erick Reyes, who was suspected of trying to forcibly enter his ex-girlfriend’s apartment, and Robert Johnson. Officers ordered Reyes to sit and began speaking with him, but their interaction with Johnson, who was unarmed and talking on a cellphone, quickly escalated,” Vox reported.

Mesa Police Chief Ramon Batista reportedly told reporters that he was releasing the video to the public to be as transparent as possible about the incident. Batista said he was not aware of the incident until the surveillance video was sent to the police department by a civilian.

“I don’t feel that our officers were at their best,” he told reporters Tuesday when releasing the video. “I don’t feel this situation needed to go the way that it went.”

Four of the officers involved in the incident have been placed on administrative leave while the department conducts an investigation. On Wednesday, the department released additional body camera footage of the incident.

Warning: this video may contain graphic images and/or profane language.

The Mesa Police Association, which advocates on behalf of officers, didn’t agree with the footage being released so soon after the incident. “It is grossly inappropriate to release a portion of the video with no audio that does not include the full context of the encounter,” the union said in a statement on Tuesday. “Furthermore, we don’t understand why video is being released when an internal investigation has not been completed. It is important to understand that any use of force, when viewed, is difficult to watch and never looks ‘good.’”

Many in the community disagree, and claim that there have been several high-profile and violent incidents involving the Mesa Police Department in the past few years.

“Mesa has a culture of police brutality, and this affects all people that live in Mesa and travel through Mesa, and this culture needs to be cleaned up immediately,” Benjamin Taylor, Johnson’s attorney, told the Arizona Republic.

You can watch more body cam footage below:

Body cam video of Johnson in jail after the violent beating:

This is a developing story. Heavy will continue to update as more information is known.