A 30-year-old man has been indicted on charges of stealing rental cars by installing global positioning system devices in rented vehicles, tracking their location after they are returned to rental companies, and then stealing them by using copied keys, police said, the Associated Press reports.

Mitsuhisa Kobayashi, of Itami, Hyogo Prefecture, told investigators he had stolen eight cars since last spring.

Kobayashi, currently unemployed, was previously a car assembly worker and used his specialist knowledge to install a small GPS device, or a cell phone equipped with GPS, inside the cars, in locations that would carry an electric current even when the engine was turned off.

According to police sources, Kobayashi implemented the scheme with the assistance of his two former wives, who collected and took cars to and from rental firms.

On Jan. 20 Kobayashi removed the dashboard panel of a rented car, placed a small GPS device inside, copied the key and then had the car returned to a rental firm in Takarazuka in the prefecture, the police said. On the night of Feb. 8 he stole the car, worth about 2 million yen, after using the GPS device to locate it in a parking lot in Nishinomiya in the prefecture.

In December, he used the same technique to steal a 2.5 million yen car rented from the same Takarazuka firm after tracking it to Toyooka, in northern Hyogo Prefecture.

According to the AP, Kobayashi was in possession of three of the eight stolen cars when he was arrested by Nishinomiya Police Station in February. He told investigators, "I wanted to drive my favorite cars. I sold the other five cars on the Internet."