A serial killer is an individual who commits a series of two or more murders, typically with a psychological motive. These crimes are often characterized by a pattern or specific method, and the killer usually seeks to gain power or control over their victims. The motives can vary widely, including financial gain, revenge, or a desire for notoriety. Serial killers often exhibit certain psychological traits, such as a lack of empathy and a tendency toward manipulation. They may also have a history of antisocial behavior. Notable examples include Ted Bundy and John Wayne Gacy, who gained infamy for their heinous acts.