When Susan Cox Powell went missing in December 2009, the concern was palpable. Family and friends were beside themselves with worry knowing the mother of 2 boys would never leave them of her own accord. The only person who didn't show concern was the person closest to her: Her husband, Josh. 

Sources: "If I Can't Have you: Susan Powell, her Mysterious Disappearance and the Murder of Her Children" By Gregg Olsen 

"Fatal Friends, Deadly Neighbors" by Ann Rule