A 21-year-old Schwenksville man was arrested early Thursday, not long after he struck a Philadelphia police sergeant with his car in Manayunk and then took off.

Colin Murphy of the 600 block of Appaloosa Street was picked up after a tow-truck operator monitoring police scanner transmissions heard of the accident and saw Murphy's 2008 Toyota Rav-4 near Ridge Avenue and Conarroe Street, police said. The operator called police, and Murphy was stopped about a block away and taken into custody.

Police said that just before 1 a.m. Thursday, Murphy drove into Police Sgt. Joseph Cain Jr., 55, who had been assisting with a vehicle stop on the 4100 block of Main Street, then drove away.

He was charged with aggravated assault while DUI, criminal mischief, DUI, and related offenses, police said.

Cain, a 26-year veteran of the department, was taken to Einstein Medical Center complaining of pain. He was listed in stable condition.