Serial killers are a very specific type of murderer. According to Wikipedia, the word originated from an FBI special agent in the 1970s, but there have obviously been people who have fit the description before that. Is there any clear consensus on the first recorded serial killer?

The same page also references Louis B. Schlesinger, a professor of forensic psychology at John Jay College of Criminal Justice at the City University of New York who suggests that medieval legends such as werewolves and vampires might actually have been serial killers, although I do not have access to the book in which he makes this claim.