Philadelphia's district attorney has vowed to make his own decision about whether to charge two young officers in the shooting death of Walter Wallace Jr and not to rely solely on the police investigation.
Wednesday's comments from District Attorney Larry Krasner came just before the city released 911 calls, police body camera video and other evidence in Wallace's death last month.
Police Commissioner Danielle Outlaw identified the two patrol officers who opened fire on Wallace as Sean Matarazzo, 25, and Thomas Munz, 26.
Neither had more than three years experience.
Outlaw also pledged to put reforms in place by late next year including more deescalation training and better co-ordination with mental health specialists.
The evidence shows Wallace, a 27-year-old black man, was killed outside his house within one minute of the officers' arrival, Krasner said.
Family members have said they called 911 to seek help as he went through a mental health crisis. Police said he ignored commands to drop a knife.
Many exchanges in the 911 tapes released on Wednesday are unintelligible.
At one point, a caller says her brother is hitting her parents; says her parents called police earlier; mentions her brother has a history of violence; and requests a medic for her parents.
The pair of police body cam videos shows police repeatedly yelling at Wallace to put a knife down and ordering bystanders to move.
Wallace rushes between cars into a street where the two officers have their guns drawn. Several shots are fired, and Wallace falls on his front.
A woman rushes to the man, screaming and crying and throws an object at one of the officers.
Bystanders turn the man over and the video shows Wallace lying on his black with blood on his chest and a brief flash of a large knife lying on the pavement next to him.
The local Fraternal Order of Police said it welcomed the release of the evidence and decried Mayor Jim Kenney's use of the term "police violence" to describe it.
"The real violence was perpetrated by a knife-wielding man, who confronted our police officers," President John McNesby said in a statement.
"These officers followed their training and police department policy. It's completely inappropriate that these officers continue to be vilified for doing their job,"
An internal affairs investigation within the police department was also underway, Outlaw said.
Black pastors joined city leaders at a news conference on Wednesday, pleading with protesters and others outraged by the police killing to remain peaceful.
The pastors said Wallace's family does not want his memory marred by more store break-ins and violence that broke out in the days following his October 26 death.