"Happy Face Killer" Keith Jesperson believes Kohberger's awkwardness and high-profile murder case make him vulnerable, and he's recommending a transfer to Oregon.

In the days after murdering four University of Idaho students in an off-campus home, Bryan Kohberger’s behavior shifted dramatically and investigators would later find that he had fixated on news coverage of the killings and began paying for items in cash – often wearing gloves – as he avoided the area of the murders.

ABC News sat down with Idaho State Police Lt. Darren Gilbertson, the lead detective in the Idaho murders case, after Bryan Kohberger was put behind bars for life.

Despite Kohberger's guilty plea in the Idaho murders, investigators still don't know his motive, who he targeted or where the murder weapon is after he covered his tracks.

Alivea Goncalves said she would not offer her sister's murderer tears. Instead she called him "pathetic," "as dumb as they come."

She told police that they planned to meet shortly after he stabbed four students, but that they stopped talking because their conversations made her "uncomfortable."

Idaho quadruple murderer Bryan Kohberger transitions from county jail to maximum security prison where inmates with life sentences have nothing to lose

Bryan Kohberger was sentenced to life in prison for killing Madison Mogen, Kaylee Goncalves, Xana Kernodle and Ethan Chapin. But will we ever know why?