Agents from the Minnesota Bureau of Criminal Apprehension have gathered videos recorded by witnesses using cell phones, surveillance cameras at nearby apartments, a mobile police camera and an ambulance recorder. There might also be video from a camera at an Elk's Lodge, the superintendent of the Bureau of Criminal Apprehension told reporters.
But there is no dash cam from police cars or body camera video, said Drew Evans.
Jamar Clark, 24, died Monday night of a gunshot wound to the head, the Hennepin County Medical Examiner's Office said in a preliminary report.
Authorities didn't find any weapons where Clark was shot early Sunday morning when police answered a call of a woman being assaulted by a man.
Evans said officials will wait until the autopsy is done before revealing how many times Clark was shot. He also would not identify the officers, who have not been interviewed.
Evans said it would be weeks before the videos are disclosed publicly. Authorities don't want to influence potential witnesses, he said.
On Monday, a spokesman for the Minneapolis Police Department, John Elder, said Clark was shot by one officer during a struggle with police.
Evans said investigators found handcuffs at the scene and are trying to determine whether Clark was wearing them at the time he was shot.
Police have said Clark was not handcuffed when he was shot, but protesters have disputed that.
The FBI is investigating the case.
Black Lives Matter demonstration
Black Lives Matter activists protested for a third consecutive day Tuesday, CNN affiliate WCCO
reported. Demonstrators gathered in front of Minneapolis Police Department's 4th Precinct building, demanding to be given the identity of the officers involved.
The president of the Minneapolis chapter of the NAACP said she was upset the officer who shot Clark was not in jail.
"How is it that an officer can shoot someone in the head and seemingly get away with it, and not be taken into custody," Nekima Levy-Pounds told WCCO. "There is absolutely no way that the conduct of that officer could be justified through departmental policies."
WCCO reported some of the protesters hadn't left their positions since Sunday, even though it was drizzling and cooler on Tuesday.
On Monday evening, protesters shut down a Minneapolis interstate. About 200 to 300 people took part in the protest, which closed traffic on Interstate 94 for about three hours, said Lt. Tiffani Schweigart, spokeswoman for Minnesota State Police. Fifty-one people were arrested.
Protesters clashed not only with police, but also with drivers, some of whom tried to force their way through the crowd on the roadway, according to WCCO. When police arrived and started rerouting traffic off the interstate and onto secondary roads, protesters tried to block that action as well, forming a human chain across the detour.
Schweigart said police were able to clear the highway without force, but squad cars were damaged by rocks and bottles and one officer was slightly injured after being punched in the face by a protester, who later fled the scene.
Gov. Mark Dayton said he empathized with protesters.
"We share their concern and we're not indicting or convicting anyone until all the facts are known," he said, according to WCCO. "We share their regret that this incident occurred."