It's an auto thief's nightmare: The car he has just stolen begins to talk, telling him to pull over. Police officers appear out of nowhere, creeping up from behind. Without warning, the engine shuts off, and the doors lock.

Prince William County police hope such scenarios are a matter of weeks away. Next month, the department will be the first in the region to start using a specially equipped "bait car." And they hope the car, which will be linked to a satellite tracking system, will be stolen.

About 60 jurisdictions across the country use the technology, which links cars to the Global Positioning System, a satellite network. The system lets police find the cars and follow them.

The cars also come equipped with audio and video recorders to collect evidence, and remote controls that enable police officers to shut off the engine, lock the doors or honk the horn from a monitoring center. Perhaps the biggest advantage is that police don't have to watch a bait car as they wait for it to be stolen.

"The majority of your auto thefts occur with no witnesses, leaving the apprehension of the criminal a pretty hit-or-miss thing," said Prince William Sgt. Tony Spencer. "With this car, we actually have something that you don't have to devote man-hours to that can specifically target a particular crime. It's a Prince William County officer in metal, with no heart and a lot of brains."

Prince William Police Chief Charlie T. Deane said the effort comes at a time when the Washington area has one of the highest auto theft rates in the nation. In Prince William, about 600 cars are stolen each year, and in October, a car was broken into every 4 1/2 hours.

"There's no doubt that a few criminals can steal an awful lot of cars before they are caught," Deane said. "Once the word gets out [about the decoy program], people will think twice, because they won't know which cars are the decoys."

Spencer said police will leave the bait car in places with high rates of auto theft. The satellite tracking system can pinpoint the car's location to within 100 feet, enabling police to intercept it after it moves. Those monitoring the car will be able to talk to the thieves and to hear their conversations, giving them a chance to alert officers to potential dangers.

Nelson Rochester, government affairs manager for San Antonio-based ATX Technologies, said the company's On Guard program has met with considerable success since it began in 1997. ATX, which primarily provides security services to private clients, monitors about 100 bait cars nationwide. Since 1997, the program has led to the arrest of more than 500 auto theft suspects.

Prince William and other jurisdictions pay nothing for the cars, which are donated by insurance companies eager to cut losses to car theft. ATX donates its monitoring service as well.

In Minneapolis, where the program has been used for two years, car theft has been reduced citywide by almost 25 percent, with some areas dropping 40 percent. Minneapolis police Sgt. Joline Lindner said the bait car fleet has been expanded to 10 vehicles because of the program's overwhelming success.

"We never expected as drastic a reduction as we've seen," Lindner said. "And it's a slam-dunk case if you get caught."

Lindner said the program has yielded more than 100 prosecutions in Minneapolis, and she said almost every suspect pleads guilty once they see videotape of the theft. None of the cases has made it to trial, so the tactic has never been challenged in court.

American Civil Liberties Union officials said that the organization likely will want to review the program. Albert A. Foer, chairman of the ACLU of the National Capital Area, said he feels the program "has the feeling of something the state shouldn't be doing."

"This has the feel of the state putting something valuable out in front of a citizen and inviting him to steal it, which carries the flavor of entrapment," Foer said. "Entrapment might be a difficult case to make, but we're interested any time technology is used to facilitate the catching of criminals."

Prince William County Commonwealth's Attorney Paul B. Ebert said he doesn't consider the tactic improper. "Just providing [people] the opportunity to commit a crime," Ebert said, "doesn't entrap them into committing that crime. . . . The mere fact that you've got this program in place may very well deter some people from committing the crime."