H. H. Holmes was known for robbing graves, stealing horses, insurance fraud, and... murder. The United States' first serial killer allegedly had up to 200 victims fall prey to the soundproof rooms, secret passages, trapdoors, acid vats, pits of quicklime, gas chambers, and crematorium in his 'Murder Castle'.   Twitter and Instagram - @biarpodcast Facebook - Bug in a Rug Email us your ideas at [email protected]   Sources: Did Serial Killer H.H. Holmes Really Build a ‘Murder Castle’? | HISTORY The Enduring Mystery of H.H. Holmes, America's 'First' Serial Killer | Smithsonian Exhumation confirms gravesite of notorious Chicago serial killer H.H. Holmes - Chicago Tribune H.H. Holmes: Biography, Serial Killer, Murderer H.H. Holmes - Crime Museum H. H. Holmes - Wikipedia Mass murderer Dr H H Holmes: The story of the Chicago Murder Castle, plus Benjamin Pitezel & his other victims - Click Americana Michigan Today » A double dose of the macabre Murder Castle ‑ H.H. Holmes, Chicago World's Fair & Layout | HISTORY New Master List of HH Holmes Victims – Mysterious Chicago St. Louis Post-Dispatch. Holmes selling Mortgaged Goods - Newspapers.com™ The Trial of Herman W. Mudgett Alias H.H. Holmes for the Murder of Benjamin ... - Herman W. Mudgett - Google Books