The Real Answer to: What Defines a Serial Killer?

If you search the internet for 'Serial Killer definition' you'll get, for the most part, the same answer, beginning with someone who kills 3 or more people ....
Extracted from my book, " The Encyclopedia of Serial Killers, from A to Z "
A serial killer, as originally described by Ronald Ressler of the FBI, is usually an individual (but may be a small group or an individual validated by a group) who murders three or more people over more than one event. The FBI recently changed this definition to...