Koenig was his only known victim in Alaska. Goeden and Bell said he never explained why his broke his own rule of never killing anyone in the town where he lived because it's easier to be connected to such a killing.
The only mistake Keyes said he made was letting his rental car be photographed by an ATM when withdrawing money in Texas.
Unlike his earlier killings, the deaths of the Curriers and Koenig received a lot of news coverage.
"He was feeding off the media attention in the end," Bell said.
That wasn't the only change. His time between murders was growing shorter.
"He talked about that time period in between crimes, that over the last few years, that became quicker," Goeden said.
During their interviews, Keyes was willing to talk about the Koenig and Currier killings since he knew authorities had evidence against him.
"It was chilling to listen to him. He was clearly reliving it to a degree, and I think he enjoyed talking about it," Bell said of the Koenig and Currier deaths. But in the other cases, Keyes wasn't as forthcoming because he knew investigators had little on them.
Keyes, a construction contractor, told investigators that they knew him better than anyone, and that this was the first time he'd ever spoken about what he called his double life.
"A couple of times, he would kind of chuckle, tell us how weird it was to be talking about this," Bell said.
Even though he was talking to investigators, Keyes didn't want his name made public in any of the other investigations, especially the Curriers, because of the fallout of publicity. He threatened to withhold information if his name got out.
"If there was nobody else that he was concerned about, I think he wanted his story out there. He wanted people to know what he did," Goeden said. "What he was worried about is the impact that was going to have on the people that cared about him and were close to him."
Keyes will be buried Sunday in Washington state.
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