Herman Webster Mudgett (May 16, 1861 – May 7, 1896), better known as Dr. Henry Howard Holmes or H. H. Holmes, was an American con artist and serial killer, the subject of more than 50 lawsuits in Chicago alone.

Despite his confession of 27 murders (including some people who were verifiably still alive) while awaiting execution, Holmes was convicted and sentenced to death for only one murder, that of accomplice and business partner Benjamin Pitezel. It is believed he killed three of the Pitezel children, as well as 3 mistresses, the child of one of the said mistresses and the sister of another. Holmes was executed on May 7, 1896, nine days before his 35th birthday.Much of the lore surrounding the "Murder Castle" along with many of his alleged crimes are considered likely exaggerated or fabricated for sensationalistic tabloid pieces. Many of these factual inaccuracies have persisted due to the combination of ineffective police investigation and hyperbolic tabloid journalism, which are often cited as historical record.