Mayor Eric Garcetti asked that witnesses to the fatal Aug. 11 police shooting of Ezell Ford in South Los Angeles come forward to assist with the investigation.
He also said during a press conference that he will order that the autopsy on Ford -- which has been under a security hold at the LAPD's request -- be released by the end of the year.
LAPD Chief Charlie Beck said he does not want to permanently bar access to the autopsy report.
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The chief said the Ford case has been a "difficult investigation" for the department, and he asked that anyone who witnessed the shooting to contact police, the District Attorney's Office, or the office of LAPD Inspector General Alexander Bustamante.
"If somebody feels that they do not watn to come forward to the LAPD, then that's fine with this investigation," he said. "We have given other avenues which they may use."
But community activists believe people may not come forward because they're investigating their own.
"It's still law enforcement making the call," said Earl Ofari Hutchinson of the Urban Policy Roundtable.
Ford, 25, was unarmed when officers from a gang unit confronted him on a street near his home in South Los Angeles. Officers said they shot him as he tried to grab a gun during a struggle.
Family members say Ford was mentally ill and was harmless. A friend has said she witnessed the confrontation and didn’t see Ford struggle.
The family filed a federal civil rights lawsuit in September against the department and the two officers who shot him.
The killing inspired several protests in the city.
In one demonstration, organized by BAMN (By Any Means Necessary), about 50 people gathered to chant slogans such as "No Justice, No Peace" and called for police to release the names of the officers involved.
Department officials released the names of the officers more than two weeks after the incident. They are Sharlton Wampler and Antonio Villegas.
Larry Hanna, an attorney for the officers, told the LA Times that the officers acted appropriately and "they used the level of force that was warranted."