Are psychopaths evil' & untreatable or do they suffer from a form of mental illness comparable to schizophrenia? Do they have free will? Do we? In this at once terrifying & exhilarating account neuroscientist Kent Kiehl guides us through the dark world of a psychopath's mind a disconnected place where emotion is dead & guilt is absent Drawing on groundbreaking research including personality surveys & brain imaging scans of thousands of criminals Kiehl pinpoints the biological machinery of psychopathy & offers a radical new perspective on identifying & treating the psychopaths in our midst