Prince William County police yesterday released a copy of a "contact card" filled out with a fictitious Alexandria address and telephone number, which was found inside the Dale City trailer where three young women were shot to death on Saturday.

The card, used by a developer, Ryland Homes, at the trailer sales office to contact prospective home buyers, was the only one filled out on the day of the murder, police said. It is the first evidence made public in the investigation.

Police also announced yesterday they were looking for a 1965 to 1966 model Chevrolet, two-door sedan seen driving in the wrong lane of Dale Boulevard at about the time of the killings, near the trailer where the bodies were found. The dark-color car has no chrome trim, no hubcaps was dirty, the police said.

Police efforts were bolstered yesterday by the offer of a $1,500 reward from the Prince William County Board of Supervisors and $3,500 from county residents for information leading to an arrest and conviction in the slayings.

Police, who noted yesterday it was common for people to put false information on the cards to avoid follow-up phone calls, are asking anyone who recognizes the name on the card. Phil P. Pryson, to call the police department. Handwriting on the card is being analyzed at a laboratory, police said.

Police said the address on the card, 1290 Firning St., and the phone number were false.

The investigation, which Police Chief George T. Owens called the county's most extensive criminal probe, has yet to come up with a suspect or motive in the murders of the women, who were each shot once in the back of the head, and found lying side by side in the trailer.

The county Board of Supervisors planned yesterday to offer a $5,000 reward, but it down to $1,5000 on the advice of the deputy county counsel, who said that Virginia law limits rewards by municipalities to $500 for each felony.

Police would not say who offered the $3,500 reward, saying only that it came from "county citizens."

Found dead in the trailer were SharonLake, 25, of Dale City, her friend, Deborah Warner Frank, 23, of Alexandria, and Karen Rose Scarbrough, 17, of Falmouth, Va., who was working on the first day of her first job since graduating from high school.

Lake, a first-grade teacher at Occoquan Elementary School in Woodbridge, and Frank, who worked for a consulting firm in McLean, were friends and had gone to the trailer Saturday as part of an afternoon of house hunting.