How Many People Did H.H. Holmes Kill? 'American Ripper' Investigates A Prolific Serial Killer
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Do you have your tin foil hat ready? A new docuseries premiering July 11 is putting forth a bizarre theory that notorious serial killers H.H. Holmes and Jack the Ripper were the same person. But how many people did H.H. Holmes kill? Was he as prolific as the Ripper? Or more prolific? The American murderer may not be as well known as his English counterpart… but that could soon change thanks to the History Channel's American Ripper.

In fact, the exact count of Holmes' victims has been the subject of much debate ever since his apprehension in 1894. The killer, who originally hailed from New Hampshire, moved to Chicago where he set up a hotel — later dubbed his "murder castle" — in order to prey on unsuspecting attendees of the 1893 Chicago World's Fair. According to TIME, the hotel was a veritable house of horrors, equipped with dead ends and stairways to nowhere to confuse the guests, gas chambers to asphyxiate his victims, trapdoors to move their corpses to the cellar, and a basement laboratory where he performed experiments on the bodies.

Given that Holmes eventually disposed of most of these bodies by incinerating them in a kiln, according to Biography.com (not to mention the relatively shoddy nature of Missing Persons investigations in the 19th century), a precise estimate of victims has never been established.

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There are three numbers that are typically bandied about when discussing Holmes' trail of carnage, and they could not be more different. The official number is 27; according to a recent profile of the serial killer in Rolling Stone, this is the number of victims that Holmes confessed to murdering after his arrest. The profile also suggests that Holmes may have killed over 200 people — although there's no evidence to indicate that such a large number is anything other than hyperbole.

Conversely, Rolling Stone also reports that modern experts believe Holmes only actually killed nine people. Indeed, Biography.com alleges that many of the people Holmes "confessed" to killing actually turned up alive and well after his execution, lending credence to the lower estimate; the site also claims that any body counts in the hundreds are nothing but "exaggeration."

If this lower estimate of is indeed the reality, then Holmes' body count in America actually does line up fairly closely with Jack the Ripper's body count over in London around the same time. The exact number of Ripper victims is also unknown; while there are an accepted five "canonical" deaths linked to the serial killer, some theories credit the Ripper with 11 total victims, according to the website for London's official Jack the Ripper tour.

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While the name "H.H. Holmes" may not be as iconic yet as Jack the Ripper, that could soon change — thanks to renewed interest in his case from both American Ripper and the upcoming adaptation of Erik Larsen's 2003 true crime novel The Devil In The White City, which is being turned into a feature film directed by Martin Scorsese and starring Leonardo DiCaprio as the villainous Holmes himself.

From "murder castle" to conspiracy theories to Oscar bait… Holmes' story is a strange tale that just keeps getting stranger by the day.