An alert witness helped police catch an alleged car thief Friday night in Waianae.

A 33-year-old man called 911 around 8:50 p.m. after he observed a 23-year-old man having difficulty parking, according to police.

The caller provided police with the vehicle’s license number, which came up in the department¹s system as reported stolen, police said.

Police located the suspect at 9:10 p.m., and the witness positively identified him. The suspect was arrested on suspicion of unauthorized control of a propelled vehicle.