Dateline NBC

An arrest is finally made five years after a mother of four disappeared while she was close to her apartment in Montana.

When a graduate student is shot dead outside of her North Carolina home, a 911 caller leads detectives to believe the victim's fiance is the key to solving the case.

When a young, handsome veterinarian is found dead in his home in Montana, the mystery remains unsolved for nearly two decades.

Before time runs out, detectives race to find a Little Rock, Ark., realtor who went missing after showing a house.