The man charged with killing four University of Idaho students in 2022 pleaded guilty, capping a mystifying murder case that's long captured the nation's attention.

With a series of “yes” replies to a judge, a man accused of killing four Idaho college students pleaded guilty in exchange for life in prison and no death penalty. But left untold so far: What motivated Bryan Kohberger to commit the middle-of-the-night knife attacks and why those victims?