Eric Williams turned himself in to Fayetteville police Thursday. He's charged with robbery and assault with a deadly weapon.
Investigators say Officer Cedric McLeod, 22, was off-duty and in a convenience store when a group of men exchanged gunfire during the robbery of the store Monday morning.
Investigators say an 18-year-old suspect, Herbert Demetrius Wilson, was also shot during the incident. Wilson was charged Wednesday with attempted murder.
Police are still looking for a third suspect, Jabon Phillip Johnson.
McLeod is in good condition atDuke Medical Center.