An alert officer arrested three people in a stolen car on Monday, police said. 

The officer noticed them sitting in an idling car in Pearl City. When the officer checked the licence plate of the car, he found out that it was stolen, police said.

The officer arrested a 33-year-old Waipahu man for operating a stolen vehicle. His passengers — a 21-year-old Kaneohe man and a 22-year-old woman — were arrested for unauthorized entry into a motor vehicle. The woman also had a an outstanding warrant, police said