Serial killers are typically single white males with unstable family histories and psychological issues. They are often intelligent but have difficulties with employment and relationships. There are two main types - organized killers who plan their crimes, and disorganized killers who act impulsively. Motives include lust, thrill-seeking, gaining power or profit. Lust killers in particular derive sexual pleasure from torture and mutilation of victims. Notable serial killers profiled include Jeffrey Dahmer, who engaged in cannibalism and necrophilia, David Parker who tortured victims in a torture chamber, and Richard Chase who was driven by delusions involving blood and organs.