''I remembered her because her right arm was free,'' Sheriff Reichert said. ''And I remember her in the current of the river under about three feet of water. Her hand was moving back and forth in the current, as if she were waving, 'Help, I'm here.' It was a creepy thing. Then working that scene, we found another body on the river bank.''

But it was not until 2001, after DNA technology linked Mr. Ridgway to seven of the killings through semen and traces of paint found on the bodies, that he was arrested. Mr. Ridgway, who had been a suspect for some time and was headed for trial next year, faced the death penalty if convicted of the seven murders.

But last spring, his defense lawyers persuaded him to cooperate with the authorities, who offered him a life sentence in exchange for information about the other killings.

Court documents summarizing the interviews conducted by detectives and the sheriff with Mr. Ridgway described him as a pathological liar who, at times, tried to portray himself in ''the best possible light'' because he believed a true crime author would write a book about him.

At another point in the interviews, after Mr. Ridgway told detectives that he had sex with 10 of his victims after they were dead, Sheriff Reichert asked him: ''What was it about having sex with a dead body that you preferred over just going out and getting another woman to kill?''

Mr. Ridgway replied: ''Well, for one thing you'd have to pay for it and she was already dead.''

Like Mr. Bundy, Sheriff Reichert said, Mr. Ridgway craved attention and control and was prideful when discussing his killings. When detectives presented him with an unsolved murder to see if he would confess it, he told them: ''Why, if it isn't mine? Because I have pride in -- in -- what I do. I don't wanna take it from anybody else.''

Sheriff Reichert said that Mr. Bundy told him things he would expect the killer Mr. Bundy called ''River Man,'' to do, places the ''River Man'' would go, but that most of those actions turned out to be things that Mr. Bundy had done. It was as if Mr. Bundy was jealous of the attention the Green River killer was getting, Sheriff Reichert said.