Edmund Kemper's murders began in 1964 when, at 15, he killed his own grandparents, saying he "just wanted to see what it felt like to kill Grandma." Released after just six years, Kemper rained terror on California, raping, murdering, and desecrating the corpses of eight women, the second-to-last of which was his own mother, who he bludgeoned with a claw hammer before defiling her severed head. He then confessed and remains in prison to this day.