How Many U.S. Serial Killers Were Never Caught?

The Internet is usually good about answering your most burning questions — be they philosophical, theological, or about the world's largest pizza. But there are a few mysteries that even the infinite powers of the web can't quite crack. And today, I found that one of them is figuring out how many American serial killers were never caught. (I did find out that the world's largest pizza weighed 26,833 pounds, so at least we have that.) But for those of you who haven't immediately abandoned this article in order to furiously Google where you can find said enormous pizza, know that it's not that the Internet somehow didn't get the memo on exactly how many serial killers have evaded capture in American history. It's that, well, no one exactly knows.

Those of us who spend a little too much time thinking about creepy junk may occasionally comfort ourselves by thinking that, really, most crime stories are essentially about the triumph of good over evil. After our villain hits a certain point, the law steps in, he never breathes air again as a free man, and we all sleep a little easier at night. Except sometimes, that doesn't happen. Though our most infamous and high-profile serial killers — like Ted Bundy, John Wayne Gacy and Richard "The Night Stalker" Ramirez — all ended their lives behind bars, experts claim that the vast majority of serial killers don't ever get a flamboyant nickname or a famous mugshot. That's because no one has ever drawn a connection linking their crimes, and thus, no one even knows that they're out there, actively killing. Bet you wish you'd switched over to that pizza article now, huh? Sorry. But as your reward for sticking it out, let's try to do the math and see if we can figure out how many serial killers don't get caught.

How May Serial Killers Evade Capture?

So what are the actual numbers here? No one knows for sure, for reasons we'll get into in a second, but here's the rough math. The FBI defines serial killing as "the unlawful killing of two or more victims by the same offender(s), in separate events." Experts estimate that there are about 25 to 50 active serial killers in the U.S. at any moment, responsible for 150 murders each year. So given all that info, how many of those serial killers end up getting caught?

Criminal profiler Pat Brown noted that "it’s a small percentage [of serial murderers] that do get caught; most serial homicides go unsolved." A 2005 article in the Casper Star-Tribune estimates that about half of all serial killers are caught within a year of becoming active (though the piece doesn't clearly confirm where that stat comes from), but even with that figure in the mix, it's hard to tell.

I mean, if there are 25 to 50 serial killers operating at any time, how many of them are in their first year? Do we get a new class of 15 or so each year, eight of whom will be caught due to accidentally coming to work with blood all over their chinos? Or are we talking two new serial killers beginning work each year, to join 48 other seasoned killers who have worked out totally perfect systems and will never ever get caught?

And as Brown writes on her own website, most murders that are actually committed by serial killers never register as such to law enforcement, because they simply don't have enough evidence to link a killer to their victim — "those rare few cases with good forensic evidence are the ones that make it to court." Because of issues like this, as well as long periods between murders that keep police from connecting murders committed by the same killer, Brown claims that "[t]here are many more serial killers living outside the prison walls than inside."

Did I mention that I'm writing this alone in my house at night? It seemed like a good idea at the time, but now I'm regretting it. Please come over and hold me. I'll buy us a pizza that is not the world's biggest, but is still fairly large.

What Kinds Of Serial Killers Don't Get Caught?

I'd love to tell you that there's a specific and rare M.O. that keeps certain killers from being caught. (Especially after I made you come over and all. Also, I don't have any cash on me. Can you spot me for this pizza?) But according to Brown, the idea that serial killers have a specific M.O. is mostly the stuff of Hollywood fantasy; most serial killers will just kill whenever they get the opportunity, making it hard to find a running thread that connects their crimes.

But even when there is a common thread, that still isn't a guarantee that the long arm of the law will eventually give them the slapping-down that they so sorely deserve. Throughout American history, a number of wildly over-the-top serial killers — with specific patterns so intense that they seem to have stepped out of a CSI episode — have evaded capture. Not coincidentally, most of them ended up finding their ways to the big or small screen in fictionalized form.

American Horror Story: Coven's Axeman, for example, wasn't just another fevered product of Ryan Murphy's creepy imagination. The Axeman of New Orleans was a real criminal who murdered six or seven victims, and injured more, from May 1918 to October 1919. The Axeman dispatched his victims with an ax and sent taunting letters to the press (a technique pioneered by original evasive serial killer, Jack the Ripper). At one point, the Axeman declared that he would murder anyone in New Orleans who was not listening to live jazz music on a particular night. The citizens of New Orleans complied, and the Axeman was never heard from again.

More recently, the Zodiac Killer, who terrorized the Bay Area in the late '60s, also evaded capture, despite racking up at least seven confirmed victims (two of whom survived his attacks), being suspected in the deaths of several more people, and also sending his own taunting missives to the local press. As recently as this past January, people were still claiming to have clues to unmasking the Zodiac's identity, but nothing definitive has ever been proven.

So to answer the question that has baffled the Internet: We basically have no idea how many serial killers out there have never been caught. But there's probably a fair number of them.

However, as much as we might all enjoy freaking ourselves out about serial killers, the odds are good that they're not much of a risk to you personally. The people who are at risk of attack from serial killers are primarily members of vulnerable populations, such as homeless people, the elderly, and people who don't have a support system that will come looking for them. Serial killers also tend to attack people who have less access to protection from law enforcement or other forms of security, like many sex workers. So serial killers are a far cry from being the evil geniuses with complex plans that they're often painted as in the media; in reality, they typically use society's cruel tendency to marginalize certain groups to their own advantage. The fact that so many serial killers go undetected is mostly a sign of how we, as a culture, devalue large groups of people and do little to ensure their safety. So like in any good horror movie, it turns out that society was the real villain all along.

Images: NBC; Giphy (4)