Police arrested a man they said tracked his ex-girlfriend's whereabouts by attaching a global positioning system (search) to her car.

Ara Gabrielyan, 32, was arrested Aug. 29 on one count of stalking (search) and three counts of making criminal threats. He was being held on $500,000 bail and was to be arraigned Wednesday.

"This is what I would consider stalking of the 21st century," police Lt. Jon Perkins said.

Police said Gabrielyan tracked the 35-year-old woman, who was not identified, after she ended their relationship, showing up unexpectedly at a book store, an airport and dozens of other places where she was.

Police said Gabrielyan attached a cellular phone to the woman's car on Aug. 16 with a motion switch (search) that turned on when the car moved, transmitting a signal each minute to a satellite. Information was then sent to a Web site that allowed Gabrielyan to monitor the woman's location.

The woman learned how Gabrielyan was following her when she discovered him under her car attempting to change the cell phone's battery, police said.

Police allege Gabrielyan threatened over a six-month period to kill himself and the woman. An attorney for Gabrielyan could not immediately be reached for comment Saturday.

He faces up to six years in prison if convicted.