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SACRAMENTO, Calif. — Sacramento police released 54 new video and audio clips Monday that add new details about the department's response following the fatal shooting of Stephon Clark, an unarmed black man.

The shooting of Clark, 22, on March 18 sparked an outcry in Sacramento, California's capital, and became the latest flashpoint in a national conversation about police shootings of young black men.

The police were responding to calls of someone breaking car windows. They said they thought Clark had a gun, but he was unarmed.

The new clips, which total more than 15 hours of material, show several officers muting their microphones when they begin speaking with others and two officers administering cardiopulmonary resuscitation on Clark's motionless body more than five minutes after the shooting. They include dashboard and body camera video from officers arriving after the shooting, audio from two 911 calls and more video from a Sacramento County Sheriff's Department helicopter.

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Stephon Clark in an undated photo. Courtesy Sonia Lewis

One of the newly released 911 calls appears to come from Clark's grandfather. Earlier released video showed Clark jumping over a fence into his grandparents' side yard and then being chased by police into the backyard, where he was shot.

The male caller tells the dispatcher that someone is in his backyard "beating on my window, and I don't know what's going on." He says he can't get out of bed to see, and a woman in the background says he has "no legs."

Tommy Thompson, Clark's grandfather, lost his legs to complications from diabetes, according to Curtis Gordon, Clark's uncle. Family members said it was typical for relatives to knock on the rear window so Thompson could use a remote garage door opener to let them into the house.

The dispatcher advises the man to stay inside until police can make contact with him. Police confirmed Monday that the call came from inside the Thompson's home.

Sequita Thompson, Clark's grandmother, has said she was watching a video of a granddaughter dancing when she heard booms. She said she crawled to where her granddaughter was sleeping on the couch, pulled her to the floor, crawled to her husband and told him to call 911.

She has said the family believes in hindsight that Clark may have been asking to be let into the house when the shooting happened.

At least three new body camera videos show responding officers asking whether others have muted their microphones, a move that could spark new criticism of the department. The two officers who shot Clark muted their microphones several minutes afterward. The department now bans officers from turning off or muting cameras in most instances.

Another clip shows two responding officers performing CPR on Clark after handcuffing him.

"Come on buddy, wake up, breathe for me," one says before a medic arrives and says, "He's gone."

The first body camera video released showed that officers waited more than five minutes after shooting Clark to begin administering medical aid.

A spokesman who assisted Clark's family with the funeral, Adam Keigwin, wasn't immediately able to provide comment from the family on the new materials, including the 911 call. Stevante Clark, Clark's brother, didn't answer his cellphone, and his voice mailbox was full.