Oscar, physically and sexually abusive, stabbed his partner and two stepdaughters to death, buried the bodies, and fled the state with his two younger children. Paul, a respected investment banker, donned a Halloween mask and shot his wife and two children before turning the gun on himself. What drives individuals as different as Oscar and Paul to kill their families? Why does familicide appear to be on the rise?

In Familicidal Hearts, award-winning author and sociologist Neil Websdale uncovers the stories behind 196 male and 15 female perpetrators of this shocking offense, situating...