Lt. Raymond Evers says Temple University plainclothes officers began the pursuit at about 1:40 a.m. Sunday after a report of a man with a gun.
Philadelphia police officers joined the chase, and a uniformed officer from a marked car also began chasing the suspect.
Evers says the man turned and pointed a gun at the officer, who fired but missed.
A short distance away, the officer fired several more times, hitting the suspect in the right shoulder and neck.
Evers says the 24-year-old suspect was taken to Hahnemann University hospital, where he was listed in critical condition.
Officers reported recovering a .45 caliber handgun with an obliterated serial number.