Police Officer Jesse Hartnett was released from Penn Presbyterian Medical Center on Friday, 15 days after he was seriously injured when he was ambushed and shot in West Philadelphia by a man claiming allegiance to the Islamic State.

Hartnett, who suffered three gunshot wounds to his left arm, has undergone several surgeries but was cleared to return home Friday.

It remained unclear, however, when he will return to work.

"He's healthy enough to be home and spend time with his family, but he still has a long road ahead of him for recovery," said Officer Christine O'Brien, a Police Department spokeswoman.

Hartnett, 33, a five-year veteran assigned to the 18th District, was patrolling alone on 60th and Spruce Streets about 11:30 p.m. Jan. 7 when a man approached his squad car and, unprovoked, opened fire with a stolen police handgun.

A severely wounded Hartnett, however, managed to fire back, striking his assailant in the buttocks. Edward Archer, 30, of Yeadon, later confessed to police that he had carried out the shooting "in the name of Islam" and said he had sworn allegiance to ISIS.

Since the incident, Philadelphia police officers have been patrolling in pairs.

Archer is awaiting a preliminary hearing in Philadelphia. A hearing scheduled for Monday in Municipal Court has been postponed.