For over 20 years, sex killer Joachim Kroll had been strangling women across northern Germany. He claimed an internal force drove him, picking women walking alone in the countryside. Many were strangled with their own clothes. Then he molested them. As his killing spree increased, he started to target younger and younger victims. But even this didn't satisfy him. He killed and cooked a cat, which only drove his desire to taste human flesh. His demons overpowered him into killing, dissecting and then eating a neighbour's 4-year-old daughter. But when he was unable to dispose of the evidence, he was picked up by the police. He was charged with 12 murders but admitted to 30, making him Germany's most prolific killer in decades.