For centuries, legends and eyewitness accounts have told of a massive, hairy creature that roams the forest on two legs. While science has yet to prove the existence of this mythical man-beast, countless researchers and experiencers around the world are convinced that there is a giant, ape-like animal hiding in remote parts of the world. They point to the discovery of large, inexplicable footprints as evidence of the so-called "Bigfoot" that they hope to prove is real. But does Bigfoot actually exist?

The total disregard for life exhibited by serial killers shocks our sense of humanity and makes us question our safety and security. These sadistic psychopaths rarely show any remorse or empathy for the lives they've destroyed. How could human beings be capable of these horrific atrocities? And what causes such a murderous defect in the human psyche?