Homing In on Hidden Transmitter : Radio Device Gives Police a Leg Up on Car Thieves

In the car-theft capital of the United States, Los Angeles police are pinning their hopes on a homing device capable of leading them to stolen cars within minutes.

“If this is a success, we can make it very uncomfortable for people to steal cars--that will make them go somewhere else,” said Officer Bill Farrar, part of a team of officers studying a vehicle tracking system for the city.

The system, called Lojack, has been used in Massachusetts since the summer of 1976. There, police have recovered 99% of stolen vehicles containing the hidden homing devices, most within minutes after they are taken, Farrar said.

Los Angeles police, who have been studying the system since January, are preparing a $1.5-million grant request to bring the Lojack system to the nation’s second-largest city.

Device Hidden in Car

A Lojack transmitter, about the size of a blackboard eraser, is implanted in the car. “It could be anywhere. It might be in the engine, or under the seat. Literally, to find the thing, you’d have to dismantle the car,” Sgt. Gary Stromlund said.

When a car is reported stolen, police dispatchers would enter its Vehicle Identification Number into the state crime computer.

The state system activates the Lojack transmitter in the stolen car by sending out a personalized radio signal over the police broadcast system. Once activated, the stolen car’s transmitter emits a silent radio signal every 10 seconds.

Utilizing a system similar to triangulation, roaming patrol cars equipped with a Lojack detector pick up the radio signal and track the stolen vehicle.

A circular grid shows police the car’s direction. A blinking light and audible tone increase in intensity as the police car gets closer to the stolen vehicle.

Faced with several signals, police can lock in on a single transmitter and boost the signal to transmit every second.

Identification Process

An identification number displayed on the tracking unit tells police which car is emitting the radio signal. Police can call that number into a dispatcher, who can provide officers with the car’s make, when and where it was stolen, and possibly information on suspects.

The transmitter’s signal can be tracked by police from a distance of 12 to 25 miles, depending on the terrain. Los Angeles’ high-rises, however, bounce the radio signals back and forth, making it more difficult to get a true fix, Farrar said.

Los Angeles police have equipped two cars with the tracking unit and have conducted nearly 100 tests on the system, manufactured by the Lojack Corp., based in Braintree, Mass., Stromlund said.

In the tests, police send a patrol car into the city to find the roving transmitter. Usually, it takes only 10 to 15 minutes to find the car, he said.

“It takes a little skill and a little practice, but you learn how to track it down,” Farrar said. “You’ve got to figure where to turn and how far to go.”

Police could have a tougher time tracking down money for the system from city officials and legislators.

The program also depends on the willingness of car owners to spend up to $600 to have the Lojack transmitter installed in their cars.

The installation cost could be partially offset if the insurance industry reduced premiums for car owners with Lojack systems, Farrar said.