The Los Angeles Police Department (LAPD) will become the first law enforcement agency to outfit cars with a device that propels and sticks a Global Positioning System (GPS) onto a fleeing car.

The department will mount the StarChase LLC device in the grill of some squad cars in the fall. "Officers in the car would control a green laser light, similar to an aiming device that fixes on your target," said LAPD Lieutenant Paul Vernon on Friday. "A small dart-like device is propelled from the officer's car."

The LAPD is hopeful the GPS device will reduce the number of high-speed car chases through the city. The department conducted more than 600 vehicle pursuits in 2005, up from 581 in the prior year, said Vernon.

Rather than engage in a high-speed chase that is dangerous for the public and police, an officer can trigger the GPS tracking device from their car. The officer also will have a remote unit, about the size of a device that unlocks a car, when they're outside the patrol car.

Each StarChase unit can fire two GPS tracking devices in case the first one misses or does not stick to the vehicle. The GPS device consists of a battery and a radio transmitter embedded in an epoxy compound. The tag affixes to the suspect's vehicle and transmits its location via satellite to police headquarters where it is superimposed over a map displayed on a computer.

The GPS tag activates at impact. It transmits the car's exact position via a wireless modem. An encrypted cellular backbone delivers continuous position updates to the StarChase server that pushes location-based information to authorized users through a password-protected Web portal.

The delay between the transmission and the refresh-picture rate from the Web server is about two to three seconds. The system uses data transmission encryption to ensure security. StarChase said the platform is approved by the National Security Agency.

The LAPD expects trails to last between four and six months. The technology is still in development. A few questions remain. For example, it's not clear the optimal distance a patrol car must follow behind a vehicle in pursuit. Vernon said it's probably "similar distance an officer would be in most gun fights, which is fairly close, about 21 feet."

The GPS device is one of three new technologies the department will deploy. Others include a small Taser gun and a new crime analysis lab.