The motel handyman accused of brutally killing a naturalist last week at Yosemite National Park has told a California television station that he also abducted and killed three other women who had come there for a weekend of hiking and sightseeing earlier this year.

In a report broadcast today, KNTV in San Jose said that Cary Stayner, who was arrested this past weekend in connection with one of the four slayings, confessed in a jailhouse interview that he has fantasized about killing women since childhood and committed all of the crimes because he "couldn't help himself."

FBI officials would not publicly confirm that Stayner has confessed to all of the killings. "I cannot comment on the substance of such statements," said Nick Rossi, an FBI spokesman in Sacramento.

But other investigators say privately that Stayner, 37, has made similar statements during questioning that they are still trying to corroborate. Family members of the victims also said today that investigators have told them Stayner has admitted to all four slayings. So far, he has been charged with murder only in the death of Joie Ruth Armstrong, 26, who was found beheaded last Thursday at Yosemite.

Authorities say that Stayner denied having any role in the killing of Armstrong last week, but then confessed in detail to it shortly after they arrested him at a nudist resort near Sacramento on Saturday. Investigators also say they found evidence linking him to the other grisly slayings during searches of the room that he rents in the tiny village of El Portal, Calif., which is on the western edge of the majestic park.

Stayner has worked at the Cedar Lodge there for most of the past two years. Until the slaying of Armstrong, who taught at the park, FBI investigators had ruled him out as a suspect in the deaths of the other three women. They were last seen alive in a parking area outside the Cedar Lodge one night in February.

The homicides have stirred enormous concern across the West, because Yosemite, which is about 150 miles east of San Francisco, is a premier vacation destination, drawing 4 million visitors a year. The latest twist in the case also is raising questions about how the FBI and other police agencies across Northern California have managed their huge investigation. Until now, their chief suspects in the killings had been several other local men with criminal pasts whom they have held in custody since the spring on parole violations.

But now Stayner, who is being held in Sacramento without bail, apparently is claiming responsibility for committing and then trying to meticulously cover up all of the murders.

KNTV quoted him as saying that he strangled two of the women -- Carole Sund and a teenage friend of her daughter, Silvina Pelosso -- inside their cabin at the Cedar Lodge, then killed a third near a mountain lake. Authorities say that victim, Juli Sund, 15, had her throat slashed in much the same manner as Armstrong. According to the television station, Stayner said he acted alone and was driven by "voices in his head."

In the interview, Stayner also described how he tried to mislead investigators by leaving wet towels in the room of the three women to make it seem as though they had taken a morning shower and left the lodge peacefully even though he had already abducted them the previous night. According to the report, Stayner even said that he tried to confuse investigators on the case by deliberately dropping Carole Sund's wallet on a busy street in Modesto, Calif., which is more than 50 miles west of Yosemite National Park.

Stayner is scheduled to be arraigned next week. Law enforcement officials are preparing to present more murder charges against him, but they say they have not yet dismissed the possibility that he had accomplices. Investigators said they became suspicious of Stayner after his truck was seen near Armstrong's cabin and he failed to report to work for the first time in more than a year last Friday.

Meanwhile, law enforcement officials in three California counties said today that they want to question Stayner about a few unresolved murder cases this decade that involved decapitated victims. And officials in Merced, Calif., the small town where Stayner grew up, said they are reopening an investigation into the mysterious shooting death of Jesse Stayner, Cary's uncle, nearly a decade ago with his own gun.