Men commit murder 10 times more often than women. But just because a woman's fingerprints aren't at the crime scene doesn't mean her fingerprints weren't on the plan. We look at some memorable cases of men killing for their sweethearts.

Gypsy Rose Blanchard and a former boyfriend are in prison for the murder of Gypsy's mom, Dee Dee Blanchard, who was believed to have an attention-seeking psychological condition, Munchausen syndrome by proxy. We speak with Gypsy Rose's father, Rod Blanchard.

Gayani DeSilva, M.D., a child and adolescent psychiatrist and author, tells us about the warning signs of Munchausen syndrome and why cases involving the disorder—like that of Gypsy Rose and Dee Dee Blanchard-—are so horrifyingly fascinating.