Calvin S Hall Vernon J Nordby

The provided Wikipedia extract defines a serial killer, generally understood as someone who commits multiple murders over a period of time with pauses between events. The Federal Bureau of Investigation (FBI) offers a specific definition, characterizing serial murder as a sequence of at least two killings carried out as distinct incidents, typically by a single perpetrator acting alone.

The article highlights that the United States has a disproportionately high number of documented serial killers globally. Data from Radford University's Serial Killer Information Center indicates that the U.S. has more recorded serial killers than the next ten countries combined. The source also lists categories for identified and unidentified serial killers within the United States, alongside related topics such as rampage killers and mass shootings.