Marie Malvar had been gone a few months longer, snatched by the stranger in the burgundy red pickup truck driving off into the night, even though her boyfriend tried to follow. The trauma of her disappearance, exacerbated by her father’s certainty that he had found her killer’s house but couldn’t go inside, had pretty much destroyed her family.

Ex-commander of the task force Frank Adamson believed that Bob Fox of the Des Moines Police Department should have taken the concern of Marie Malvar’s father and boyfriend more seriously in 1983 when they took him to the house where Ridgway lived. They were sure the dark red pickup parked in his driveway was her abductor’s vehicle. Had the Des Moines police gone inside, they might not have saved Marie, but it was possible they could have found evidence of a crime and stopped further killings.

For a long time, the Malvars had gathered on April 1 to celebrate Marie’s birthday and pray for her safe return. No longer. Marie’s parents were long-divorced and her father was living in the Philippines and remarried with a young daughter he’d named after his missing Marie. Her mother was in California, ill and suffering from dementia, with Marie’s only sister, Marilyn, caring for her. Her four brothers were scattered.

But at last the searchers had found Marie’s earthly remains, only bones now, in a deep ravine near Auburn where someone had thrown her away. With each new discovery of partial skeletons secreted in the wilderness, the rumors grew stronger. Ridgway had to be telling the task force searchers where to look; they couldn’t be so unerring in their discoveries unless someone had mapped it out for them.

The rumors were correct, of course, but they didn’t go far enough. Gary Ridgway’s attorneys had successfully plea-bargained in their fight to save his life. But it would be months before anyone officially announced that.

There was shocking news yet to come. All through the summer months of 2003, the mystery about where Gary Ridgway was being housed remained. He wasn’t in any jail, any hospital, any prison. At least there was no record of his being there, and it seemed impossible that someone as infamous as a suspected serial killer could be hidden for months. There were new reports that were disquieting: Ridgway was said to be housed in a two-bedroom apartment under secure guard. Surely, that couldn’t be. How could he be living in comparative luxury after what he was alleged to have done?

Finally, when the gossip swelled, Katie Larson was instructed to announce where he was. Gary Ridgway wasn’t residing in any comfortable apartment. Not at all. He had been living, quite literally, with the Green River Task Force investigators—in the office complex where they worked each day. It was the last place anyone thought to look. No police agency had ever taken such a bold step. During their frequent brainstorming sessions, someone had come up with the idea and the detectives and prosecutors who first scoffed at the idea began to toss it around. At that point, Ridgway had been in custody for six months and hadn’t given up any secrets, protected as he was by his flying buttress wall of attorneys. In the county jail, other inmates watched what went on, and they were quick to tell each other and their visitors what Ridgway was up to and who was coming to see him. But now everything had changed.

In order to get inside the head of the one person in the world who could tell them whom he had harmed, why he had done it, and where he had secreted their bodies, the Green River Task Force investigators decided to do something off the charts. Although he didn’t appear to care about the lives of anyone else, Ridgway wanted to live. That’s true of most serial killers whose own survival is paramount. Behind closed doors, the prosecutors and the defense team had come closer to a decision everyone might be able to live with.

It was difficult for the detectives. No investigative team had ever agreed to spend so much time with a cold-blooded killer. But there he was, thirty feet from Sue Peters’s desk, sleeping on a mattress in a barren, closely guarded room. He was a constant, malevolent presence. When Peters came to work, Ridgway called out “Hi Sue!” and she forced herself to answer back cheerfully. He learned the names of most of the personnel in the task force office, and he seemed to think that it would be like his days back at Kenworth, where he was always smiling and trying to make conversation with people.

It was like having the fictional Dr. Hannibal Lecter living down the hall, albeit a far less charismatic “Lecter.” Cocooned, however sparsely, in terms of the amenities of life, Gary Ridgway was a captive—but he had a captive audience, too. As Ted Bundy had once delighted in the attention paid to him by Florida detectives after his 1978 capture, Ridgway would now be able to discuss the ghastly details of his crimes. He was a macabre champion of sorts. He held records that no one else would want to brag about.

Up to the moment of his arrest, Ridgway had been a nonentity, a boring little man of meager intelligence, a joke, someone to tease, and, worst of all for his ego, someone to ignore. But beginning in mid-June 2003, he made himself available as a subject who was quite willing to participate in long hours of questioning, day after day after day. He loved it. He had always found pleasure in demonstrating his expertise in the art of murder, and he was talking to his ideal audience—the very detectives who had faced his deadly handiwork for so many years. He knew that psychiatrists and psychologists, homicide detectives and F.B.I. agents were curious about him, and he enjoyed being the center of attention.

For his questioners, it was exhausting, disgusting, shocking, frustrating, and horrific work. And sometimes, yes, boring, as Ridgway often repeated himself or stumbled awkwardly as he searched his memory in vain.

After the public found out where he was living, and that he was admitting his crimes, there would be yet another shocking revelation about Gary Ridgway. One of the faces in the telephoto shots of the cars full of investigators that turned into the woods and mountains should have been familiar. Anyone who watched television or read the papers knew that face. Gary Ridgway accompanied the task force investigators on what they called “field trips.” He had been hidden in plain sight.

Except when they were in deep woods, Ridgway was never allowed to get out of the police units; that might have allowed someone to recognize him. But he was there, an interested spectator as well as a guide who led detectives back to where he’d left the bodies of his victims more than twenty years earlier. In order to learn what they needed to know, detectives had to allow him to revisit these sites that he had returned to often over the years of his freedom. He brightened, smiling in anticipation, as they got closer to his trophy areas.

And no one outside the investigation ever suspected.

Ridgway was guarded on every side and hampered by handcuffs with chains attached to a chain on his waist, along with leg irons. There was no chance he could escape. He rode in a locked police vehicle with two detectives accompanying him and two more in a car following. Prosecutors and his own attorneys were also in the search parties.

“He never knew when we were going,” Sue Peters recalled. “We might wake him up before the sun rose, or take him in the middle of an interview. He had no forewarning. He liked the field trips, but we couldn’t help that. Whatever he was reliving, it was something we had to know.”

For the most part, the interviews themselves were handled by four Green River detectives: Randy Mullinax, Sue Peters, Tom Jensen, and Jon Mattsen. Occasionally, psychiatrists spent hours with Ridgway, and Dr. Mary Ellen O’Toole from the F.B.I.’s Behavioral Science Unit flew in to talk with him in her soft, feminine voice, her eyes unblinking as he spoke of his perverted fantasies. “We were relieved when the F.B.I. or the doctors talked to him,” Peters remarked. “It gave us some time away from him.”