When young mother Susan Powell vanished from her Utah home one early morning in December 2009, police suspected her husband, Josh Powell. But with no body and only circumstantial evidence, the case went cold. Then a bizarre twist - after Powell took his children to live with his father, Steven, in Washington, police arrested Steven on voyeurism and child pornography charges. Just months later, with law enforcement on his heels, Josh Powell killed his two young sons and took his own life in a massive explosion.