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.

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.

"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.

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

The legal saga against the man who murdered four University of Idaho students may have ended Wednesday, when he was sentenced to life in prison without parole. But new details about the case are still emerging,

Alivea Goncalves, the older sister of the late Kaylee Gonclaves, spoke to him during the hearing, as he sat stoically in an orange jumpsuit.