Definitions of Serial Killers, Mass Murderers and Spree Killers
Serial Killers – Murders 3 or more victims on separate occasions. Victims are usually selected, the crimes are planned and the killer has a cooling off period between the murders. Eg: Ted Bundy, Richard Trenton Chase and Jeffrey Dahmer.
Mass Murderers – Kills 4+ people in one continuous period of time and in one location. This includes killers who murder several members of their family. Eg: Richard Speck, James Holmes and Adam Lanza.
Spree Killers – Kills 2+ victims at more than 1 location. There is no cooling off period between each murder. Eg: Robert Polin, Seung-Hui Cho and Robert Steinhauser.