Sometimes it’s easy to classify a genre. Stories with demons are horror. Stories involving criminal behaviour are crime stories. It’s easy, so we think. But recently there’s been a habit by the horror industry to steal crime fiction’s thunder with the “serial killer” story.
Serial killers are a relatively recent phenomenon in terms of their actually being recognised as a bona fide phenomenon. There have been instances throughout history of serial murderers, but the phrase “serial killer” erupted sometime around the thirties of forties. Quickly, due to the horrific nature of their crimes, serial killers were used as the basis for a number of novels. Multiple murderers who strike without pity or remorse make for a scary adversary. They are the ultimate darkness against which we shine the torch of our own morality. They can be excellent foils for society illuminating hypocrisy or that which we neglect.

And recently they have become the ultimate bogeyman.
It was the invention of Hannibal Lecter that really blurred the lines. He was a horrific character and yet too grand guignol to be properly real, particularly by the third book in the sequence. He was the boogey-man. He was a respected member of society who killed simply because he could. He was defiant at an explanation for his behaviour. He was a force of nature, much like the aforementioned devils of the horror novel. Indeed, this template of the serial killer as a force for evil, a reflection of our twisted times, has led to his inclusion in the ranks of horror. Next time you look at the racks of the horror shelf, just check how many serial killer books there are mixed among the usual grotesqueries.

But the essential difference between the crime fiction serial and the horror serial lies in this idea of the boogey-man. While the crime fiction serial killer may indeed be some kind of boogey man, ultimately he is understandable on some level. He is evil, but evil as a product of his twisted childhood. Many of the horror genre’s serial killers are bloodthirsty beasts who were merely born that way. They are Michael Myers in Halloween, even as children they are “pure evil”.

This pure evil aspect makes them somehow other than human. Returning to Michael Myers (in the first Halloween movie where there was no true hint of the supernatural about him other than his ferocious strength and anger) this serves to alienate the criminal from humanity. In the crime thriller, the serial killer often has intensely magnified human aspects and frailties. Often it is the person’s weakness that leads them down the road to their blood lust.

In James Ellroy’s early novel, Silent Terror (Killer on the Road) we are taken through the formation of a serial killer to his ultimate incarceration. While, unusually for a crime novel, this is through the killer’s POV, the novel is not horror in the sense that the aspect of the killer is always human. He is a weak man in many ways, only able to truly express himself through death. Perhaps worryingly, also, Silent Terror seems almost confessional with events in the killer’s early life echoing (albeit distantly) Ellroy’s troubled adolescence.

This presentation of the serial killer as protagonist is unusual in crime fiction, although not in horror. Possibly the reason for this is that horror, in its efforts to disturb, lens itself easily to the presentation of a warped psyche. Hence, the final novel in the Lecter trilogy (Hannibal) is more horror than crime, presenting to us almost first hand Lecter’s unusual and warped thought processes.
Generally, however, in crime fiction we’re presented with the serial killer as antagonist, often invisible to the protagonist for much of the novel. Most of the time they exist somewhere close to the protagonist, a boss or colleague. Examples of this include Michael Connelly’s superb The Poet or Mark Billingham’s excellent London-based thriller, Sleepyhead.

But it’s hard to separate entirely the horror serial killer from the criminal serial killer. In fact much of the time it feels like they’ve stolen something from us, warped it into their vocabulary and then slipped into the night before we even knew what was happening. Of course, there is no denying that crime and horror have much in common: a sense of outrage at atrocities beyond our control. A sense of disorientation at being thrust into a world outside of our normal rules and boundaries and in this respect the character of the serial killer slips seamlessly into the shadows of both worlds. He is both a human agent and something other than human; obeying a subset of rules that law-abiding citizens cannot comprehend. The serial killer can be both a terrifying manifestation of evil and a parable of human weakness. The extreme nature of their crimes can be overly dramatic, sometimes utterly unbelievable (in the opinion of the author, this mainly occurs within the horror genre where the serial killer is more extreme, sometimes to an almost ridiculous level) but can also serve to point to more realistic problems within society.