Serial killers commit heinous acts that are unimaginable to the average human being. Identifying the motive behind acts of violence such as murder is something doctors have researched for decades.

It seems obvious that anyone who willfully and repeatedly commits murder is a psychopath: remorseless, egotistical, manipulative, and cruel. Think of Ted Bundy, Dennis Rader, or John Wayne Gacy.

Editor’s Note: This story contains graphic descriptions of violence. For decades, criminologists and true crime documentaries have attempted to understand what causes serial killers to commit the ...

More than 5,000 serial killers have been documented throughout human history, spanning a wide range of motives, behaviors and backgrounds. By studying these cases, we can gain insight into the complex ...

Psychopaths and sociopaths are diagnoses that are often associated with serial killers. But for those of us that are not experts in the field of psychology, what do these disorders actually mean?

(CNN) -- For decades, criminologists and true crime documentaries have attempted to understand what causes serial killers to commit the atrocities they do. Dennis Rader, John Wayne Gacy, Jeffrey ...

CLEVELAND, Ohio (WOIO) - What makes a serial killer? That’s a question that has been researched for decades. We’re exploring the psychology behind serial killers, after we highlighted a series of cold ...