By Marilia Brocchetto, CNN

(CNN) -- An attorney for the family of Stephon Clark, the 22-year-old black man shot and killed by Sacramento Police, said police showed no "humanity" toward Clark after he had been shot.

"While he laid down on that ground dying, they waited six minutes. And then they go over to him after that and they put him in handcuffs," attorney Benjamin Crump told CNN's Dan Simon.

Crump also noted that shortly after that, police muted their body cameras.

"Why didn't you try to help him?" the attorney asked.

Crump -- an attorney who previously represented Trayvon Martin, Michael Brown and Tamir Rice, three young unarmed black men fatally shot by police -- was retained by Clark's family late last week.

Speaking to CNN on Sunday, Crump said Clark's death should not be "swept under the rug." Crump also called for accountability from both sides, and said he will be exploring "every legal remedy possible" in search of justice.

Clark was shot and killed March 18 in his grandmother's Sacramento backyard by officers who believed he was pointing a gun at them, according to police. No weapon was found at the scene. The only item discovered was a cell phone, police said.

Officers fired 20 shots, hitting Clark multiple times, police told CNN affiliate KOVR.

Sacramento Police released body camera video of the incident that also showed that the officers did not immediately provide Clark with lifesaving efforts, instead waiting until other units arrived at the scene.

"There's great mistrust" between communities of color and police, Crump said.

"The only way we can bridge this divide of mistrust is to have transparency and accountability," he said.

Crump will hold a news conference Monday in front of the Sacramento Federal Court regarding the case.

Two officers -- one of them black -- have been placed on paid administrative leave pending the outcome of a use of force investigation.

Body camera video captured the shooting

The shooting happened on March 18 after 9 p.m., when Sacramento officers responded to a report that a man had broken car windows and was hiding in a backyard. They pursued a man who hopped a fence and was in a backyard.

The shooting was captured by the two officers' body cameras and a police helicopter; that footage was released on Wednesday in an effort to be transparent.

The body camera videos show the brief encounter between police and Clark, lasting less than a minute.

Police said the officers entered the front yard and saw the suspect along the side of the home. The man "turned and advanced toward the officers while holding an object" extended in front of him, according to the police account.

"Show me your hands!" one of the officers yelled. "Gun, gun, gun."

Seconds later, officers opened fire as they took cover near a wall.

As more police arrived at the scene, someone is heard asking, "What did he have on him?"

An officer responded "... something in his hands. It looked like a gun from our perspective."

Clark's family has disputed the police account.

"This was an unnecessary killing of an unarmed black man yet again," Crump told CNN. "What we saw in that video was not reasonable well-trained officers."

Police said they found at least three vehicles with damage they believe Clark caused, as well as an adjacent residence with a shattered sliding glass door. Deputies in the helicopter witnessed him shatter the door, police said.

Stevante Clark told HLN his brother "wasn't a thief."

The Rev. Al Sharpton, the prominent political activist, has pledged his support for Clark's family and said he would be in California to help them fight for justice, according to a statement from his organization.