Investigating Four Types of Serial Killers

In my Emily Stone Thriller Series, Emily Stone goes up against a ruthless, diabolical and somewhat eccentric serial killer in my thriller Dead Game.  This serial killer "Samuel" uses his unique signature as a "voyeuristic" serial killer to commit his crimes.  I created Samuel to be a "power and control" and perhaps a bit of "hedonistic" type of serial killer.  In Dark Mind, the serial killer known to readers as "Keo" has a much different approach that would be considered to be a "mission" or ...