A video posted to social media appeared to show the man, later identified by officials as 27-year-old Walter Wallace, circling around a parked vehicle and walking toward officers as they backed away from him, shouting, "Put the knife down!" Both officers then fired at Mr Wallace "several times", Ms Little said. Sgt Gripp said police told him to drop the knife but he wouldn't and kept approaching the two officers.
The two officers each fired at least seven rounds - at least 14 total shots - but could not say how many times Wallace, 27, was struck. At least one witness told The Philadelphia Inquirer the officers were "too far from him", and said bystanders were trying to deescalate the situation.
Officials with the Fraternal Order of Police, the union representing officers in Philadelphia, said the officer injuries were unacceptable and called for public patience as the investigation into the shooting continued.
Wallace was hit in the shoulder and chest, Little said.
The people of West Philadelphia are enraged after Walter Wallace Jr. was killed in front of his mother. The looting occurred not near the protest, but in University City, Overbrook Park, as well as Center City and West Philadelphia.
Police in riot gear, reportedly requesting to use tear gas, were deployed to the area where they were verbally and physically assaulted by hundreds of Black Lives Matter rioters who threw bricks and other objects at officers.
Wallace's father, Walter Wallace Sr. later spoke to the media where he revealed his son had been suffering from mental health problems. "The officer is reported to be a 56-year-old female sergeant who suffered a broken leg after being hit by the vehicle".
The shooting sparked a wave of protest in America's sixth largest city. He pushed her away, and then turned to walk toward the police.
"Why didn't they use a Taser?" he asked, referring to an electrical stun gun sometimes used to avoid deadly force. The video swings back towards Wallace to show him limp in the middle of the street.
Police appeared unable to contain the community's furious response to their having shot a Black man to death in the middle of the street in the middle of the day.
No officers or bystanders were injured in the initial confrontation, Little said.
It is unclear in the video if he had a knife.
The person filming the video yells, "Y'all ain't have to give him that many shots". The names of the officers who fired the shots were not immediately disclosed. Protesters set a police vehicle ablaze and more than 30 were arrested. He added that both officers were wearing body cameras.
In an official city statement, Philly Mayor Jim Kenney said, "I have watched the video of this tragic incident and it presents hard questions that must be answered". Every single encounter between Black people and police officers is fraught with risk, and the only sure way to keep Black people safe from police violence is to limit their interactions with the police.