"I never got any bad, weird, scary, odd vibe from him in any way, shape or form," says Paul Adelman, an Anchorage attorney who first hired Keyes as a handyman in 2008.
Keyes' live-in girlfriend also was floored to learn of his double life, according to David Kanters, her friend. "He had everyone fooled," Kanters told The Associated Press in an email. "THAT is the scary part. He came across as a nice normal guy." (She did not respond to numerous requests for comment.)
Keyes blended in easily. "He was not only very intelligent," Doll says. "He was very adaptable and he had a lot of self-control. Those three things combined made him extraordinarily difficult to catch."
Keyes also was meticulous and methodical, flying to airports in the Lower 48, renting cars, driving hundreds of miles searching for victims, prowling remote spots such as parks, campgrounds and cemeteries. The Koenig case was an exception; it was in his community.
In one recorded interview, Keyes discussed his methods:
"Back when I was smart, I would let them come to me," he said, adding that he would go to isolated areas far from home. "There's not much to choose from ... but there's also no witnesses."
Keyes was proud he'd gone undetected so long. When asked for a motive, Anchorage police officer Bell recalls, Keyes said, "'A lot of people ask why and I would be like: Why not?'"
"He liked what he was doing," says FBI Special Agent Jolene Goeden. "He talked about getting a rush out of it, the adrenaline, the excitement."
Goeden says Keyes provided information for eight victims, some more specific than others. He also alluded to other victims, and said he killed fewer than 12 people altogether. In one case, he claimed a body was recovered and the death ruled accidental; he wouldn't say more.
Investigators say they independently verified almost everything he told them. "It would have been impossible to make some of these details up," prosecutor Feldis says.
They tried to get Keyes to identify more victims. But he balked at even providing their gender.
There was an exception.
Shortly after Keyes confessed to Koenig's murder, the prosecutors told him they knew he'd killed others and said his computers were being searched. Keyes knew he'd stored information in them about two victims.
It was time to clear up a mystery in a small town 3,000 miles away.
It was about 8 p.m. on April 6, 2012, and police Lt. George Murtie was home in Essex, Vt., when a local FBI agent called.
Nearly 10 months had passed since Bill and Lorraine Currier, a couple in their 50s, had disappeared. They were presumed dead. Leads were still trickling in, but Murtie was surprised to hear authorities in Alaska had a man in custody who'd confessed to killing the couple and disposing of their bodies in an abandoned farmhouse.
An Essex officer for 28 years, Murtie knew every inch of his community, including the location of that farmhouse. He headed out there that night with another detective, only to discover it had been demolished. They checked some nearby buildings but found nothing.
Several weeks later, when Murtie questioned Keyes by phone, he found him matter-of-fact when discussing how he'd killed the Curriers.
"I would describe it as if I was talking to a contractor about the work I was going to have done and he was describing the work he had done in the past," Murtie recalls. "There was no emotion or anything. Just flat."
Keyes confirmed details of a nightmarish sequence of events later outlined by Vermont authorities:
On June 2, 2011, Keyes flew into Chicago, intending to kidnap and kill. He carried a gun and silencer. He drove more than 750 miles to Essex, a bedroom community just outside Burlington. He checked into a motel he'd stayed at in 2009 — he buried weapons and supplies in the area at that time — and began scouting a house that suited his purposes: No children or dogs. No car in the driveway. A place he could be reasonably sure of where the bedroom was located.
In the early moments of June 9, Keyes cut the phone lines and removed a window fan to enter the garage. Grabbing a crowbar, he smashed a window into the house and, wearing a headlamp to navigate the darkness, rushed into the Curriers' bedroom. He forced them into their Saturn and bound them with zip ties.
They drove a few miles to the farmhouse where Keyes tied Bill Currier to a stool. Going back to the car, he saw Lorraine Currier had broken her restraints and was running toward the road: Keyes chased and tackled her, forcing her back to the building.
Bill Currier had somehow broken the stool and was shouting, "Where's my wife?" Keyes hit him with a shovel, then shot him. He sexually assaulted and strangled Lorraine Currier and put both bodies in garbage bags. He then drove into New York state, and dumped the Curriers' stolen gun and parts of the weapon he'd used into a reservoir in Parishville, N.Y. FBI dive teams recovered both. Authorities were unable to find the Curriers' bodies.
Murtie was struck by Keyes' confidence.
"There was an enormous risk he had to take to go into a neighborhood he's unfamiliar with, into a house of people he's unfamiliar with and remove them in their own vehicle," he says. "A rational-thinking person would think the chances of getting caught are very high."
During the interviews, Keyes sometimes clammed up and threatened to stop talking if publicly identified as a suspect in the Curriers' murders. Vermont authorities held off as Alaska investigators pressed for more information.
"Why don't you give us another name?" asked Russo, a federal prosecutor.
Keyes was conflicted — he wanted his story out there, but worried about the impact it would have on friends and family (he has a daughter believed to be 10 or 11), says Goeden, the FBI agent. He rebuffed all appeals to bring peace to others.
"Think about your loved ones," Doll urged. "Wouldn't you want to know if they're never coming home?"
He mulled it over and returned another day with his answer.
"I'd rather think my loved one was on a beach somewhere,' he said, "other than being horribly murdered."
Israel Keyes never provided another name.
He was found dead Dec. 2, three months before his scheduled trial in the Koenig case. The FBI is analyzing his two bloodstained pages, with writing on both sides, but they apparently don't contain victims' names.
His suicide leaves investigators and Koenig's family disappointed, angry and frustrated.
"We deserved our day in court and we didn't get it," says James Koenig, Samantha's father.
Months before Keyes' past was disclosed, Koenig believed his daughter was not his only victim. He and volunteers set up a Facebook page called, "Have You Ever met Israel Keyes? Possible Serial Killer." It includes photos of Keyes and maps.
Meanwhile, investigators have used Keyes' financial and travel records to piece together a timeline of his whereabouts from Oct. 4, 2004, to March 13, 2012. He traveled throughout the United States and made short trips into Canada and Mexico.
The FBI is seeking the public's help. On Jan. 16, a Dallas bureau press release stated Keyes was "believed to have committed multiple kidnappings and murders" across the country starting in 2001. It's looking for anyone who had contact with him on Feb. 12-16, 2012, when he was believed to be in various Texas cities.
More appeals are expected in other places.
FBI agents in Seattle and in Albany, N.Y., also are working with state and local authorities to try to verify tips from people who reported seeing Keyes. Unsolved homicides are being checked, too, to determine if Keyes was in the area at the time.
But definitive evidence? That'll be hard to come by.
Feldis, the prosecutor who heard Keyes' first confession, says it's likely the true scope of his crimes will never be known.
"There's a lot more out there that only Israel Keyes knows," he says, "and he took that to his grave."
AP National Writer Sharon Cohen reported from Chicago. Also contributing to this report were AP reporters Mark Thiessen in Anchorage, Alaska, Nicholas K. Geranios in Colville, Wash., and Wilson Ring in Montpelier, Vt.