An Annandale man has been arrested for secretly videotaping a woman who was renting a room in his house, Fairfax County police said yesterday.

The 32-year-old woman discovered a hidden video camera behind the wall of her room in March, police spokeswoman Mary Mulrenan said. The woman moved out of the house in the 3800 block of Hummer Road soon after but did not report the videotaping system until earlier this month, Mulrenan said.

Police said that after discovering the camera, peeking through a small hole in the wall, the woman and a friend followed a cable to the attic, where they found a video recorder. Investigators believe that the woman had been taped while undressing, or while sleeping, but Mulrenan said she was not aware of any sex acts captured by the camera.

On Tuesday morning, Martin G. Shepp, 40, turned himself in to police and was charged with five counts of unlawful videotaping. The charge is a misdemeanor, with a possible penalty of up to 12 months in jail and a maximum fine of $2,500 on each count.

No one answered the phone at Shepp's residence yesterday. He is not listed as the owner of the house in county land records. The owner could not be located yesterday.

Police believe that Shepp videotaped the woman between last July and March. Mulrenan said she did not know how investigators established that time frame, and she declined to say how many videotapes police had obtained. No search of Shepp's residence was conducted, Mulrenan said.

Fairfax police were unable to determine yesterday how many people had been charged with unlawful videotaping in recent years.

The Virginia General Assembly amended the unlawful videotaping law this year to add "any video graphic or still image record" in addition to videotapes and photographs.