In Anne Arundel County, many police officers are encouraged to take their patrol cars home at night because, officials believe, the mere sight of a parked police car can act as a deterrent to crime.

But yesterday, it became an enticement.

About 6:30 a.m., Officer Sef E. Martinez looked out the front window of his home near Cape St. Claire to discover that the blue and white 1991 Ford patrol car he had parked there the night before had been stolen.

The car, its door lock broken, was recovered about 10 a.m. in a nearby neighborhood. Its odometer showed that whoever had stolen it drove it about 10 miles. Much to the relief of the county police, there were no reports of a county police car's being involved in a crime during the hours it was in the hands of the thief.

"Our concern was that someone was going to use the car to make phony traffic stops," said Officer V. Richard Molloy, a police spokesman. Officer Molloy said whoever stole the car could have impersonated an officer, conned people out of money or committed other acts that would have "looked bad on the department."

Missing from the car after it was stolen were Officer Martinez's portable police radio, his nightstick and a wallet containing his badge and identification, police said.

The police said the thief had apparently used a spare key that had been hidden inside the car to start the engine once he had broken in. The key is also missing.

Officer Martinez could not be reached for comment.