Lt. John Stanford said officers were called to the Oxford Circle section of the city around 7:00 a.m. Saturday and found the man in the middle of the street with knife in hand.
He says the officers used the bumper of their vehicle to knock him to the ground and demanded he put down the knife. When he refused, they used pepper spray to subdue him, but he ran toward them and they fired.
Police says it took at least three officers to finally wrestle the knife from the man.
He was transported to Aria Health Torresdale Hospital where he was later pronounced dead.
Stanford said a witness corroborated the officers' accounts.
A seven-inch butcher knife was recovered.
The 23-year-old man's name has not yet been released.