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.

Two days after Bryan Kohberger’s sentencing, prosecutor Bill Thompson spoke to NBC News about the fact that the victims’ families may not ever get the answers they seek.

The newly released police documents revealed the horrifying extent of the crimes and an unnerving sighting by one of the victims' surviving roommates in the days leading up to the killings. They also indicate that at least one of the victims fought back intensely.

Bryan Kohberger faced emotional statements from victims' families in Boise courtroom, including scathing rebukes and one offer of forgiveness before receiving life sentences.

Lori Vallow Daybell was sentenced to life in prison on two murder conspiracy convictions in Arizona, marking an end to a winding legal saga for the mother with doomsday religious beliefs. Vallow Daybell is already serving life sentences in Idaho in the killings of her two youngest children and a romantic rival.