A witness reveals the truth behind a sniper shooting on Alaska's busiest highway; a bombing in rural Alaska triggers a multi-state manhunt and uncovers a yearlong revenge plot that tests family loyalties and leaves a community reeling.

An armed stranger takes Deanna and her grandmother hostage two days before Christmas; as police in South Carolina piece together a brutal murder spree, they have no idea that the killer is close by holding a woman and her granddaughter hostage.

Investigators discover two cases decades apart that are linked when a woman falls to her death in the Grand Canyon.

When detectives identify a brutalized body in the desert, they never expect she's one of many; three homicides are linked to convicted killer Phillip Jablonski, who records details of his killings in his grim audio diary.