Law enforcement officials said yesterday they are investigating whether a Stafford County carpet cleaner played any role in the slaying of three Spotsylvania girls in 1996 and '97.

On Friday, investigators obtained four warrants to gather DNA samples from Melvin Hogan, 32, and to conduct searches of his home in Stafford, his white Ford van and his business, in Triangle.

Maj. Howard Smith of the Spotsylvania County Sheriff's Office said Hogan is not a suspect, but "a lead like any other" in the slayings of Sofia Silva, 16, Kristin Lisk, 15, and Kati Lisk, 12. He has not been charged with any crime. The hair, blood, saliva and fiber samples have been sent to the FBI crime lab in Washington. Investigators said an analysis could take several weeks.

Contacted yesterday by phone, Hogan would not comment except to say, "I'm not guilty of anything."

Sofia was abducted from her home on Sept. 9, 1996. Her body was found in a stream 20 miles to the east. The Lisk sisters vanished after getting off separate school buses in front of their Spotsylvania home on May 1, 1997. Their bodies were found five days later in a river 40 miles south of their home. Investigators linked the slayings using evidence collected from the girls' bodies.

Hogan came to the attention of investigators shortly after the disappearance of the Lisks, Smith said. He was working a half-mile from the Lisk home on the day the girls vanished and was later questioned after neighbors reported seeing his white van in the area, Smith said.

At the time, investigators asked Hogan to provide samples of his DNA. He refused, and law enforcement officials said they did not have probable cause to obtain a search warrant.

Hogan was interviewed again on Oct. 11 after investigators said he approached a house on Hickory Ridge Road in Spotsylvania County and began asking a 15-year-old girl inappropriate questions.

According to a search warrant affidavit, Hogan was cleaning rugs with a co-worker at a nearby home when he first knocked on the girl's door to get directions and later returned alone to question her further.

According to court records, Hogan asked the girl if her parents or anyone else was home and then asked if he could enter the house to use the phone or talk to her. Investigators said he made several comments about her "attractive looks" and whether she was sexually active.

When Hogan returned to his job, investigators said, the girl called her father, who came home, used his truck to block Hogan's van in the neighbor's driveway and then called law enforcement officials.

Hogan, investigators said, was driving the white 1987 Ford van. The license plate was concealed by a piece of burlap.

According to the warrant filed Friday to search and remove samples of fibers, foam and fabric from the cleaning company, investigators said that "forensic evidence indicates that between the times the victims were abducted to the time their bodies were found that they were kept in a carpeted environment."

Smith said that since the investigation began three years ago, various leads have prompted investigators to take blood samples from as many as a dozen people.

"We feel confident, just like we've said all along, this case is going to be solved," Smith said. "We're still out there. We still have a task force going and people working on it full time."

Squeaky Clean Cleaners, which Hogan runs with his wife from a ground-floor office next to the Quantico Marine Base, was dark yesterday, the blinds shut. Employees at several other businesses said they noticed law enforcement authorities at the store last week.

Mary Himes, an employee of Airking Inc., the air conditioning repair business that owns the building on Fuller Heights Road in Triangle, said Hogan has rented the space for a little over a year.

Ridgecrest Court, where the Hogans have lived for about eight years, is a small town house community sandwiched between a handful of larger town house developments in the northern part of Stafford.

Staff writers Steven Ginsberg and Lisa Rein contributed to this report.