Officers were called to Brooklawn Avenue near Spooner Avenue on a report of two suspicious males looking into parked cars just before 8 p.m., police said.
Officers found the pair, one of whom was carrying the firearm parts in a backpack, police said.
Naim Asad Muhammad, of Bridgeport, was arrested and charged with possession of high-capacity magazines, police said. He was held on $1,000 bond and arraigned Monday.
Click here to follow Daily Voice Fairfield and receive free news updates.