Born as Herman Webster Mudgett in 1861 be would grow up to be one of the first known serial killers in the United States under the alias of Dr. Henry Howard Holmes. The exact number of victims is unknown but is thought to be in the hundreds. There were also ties to murders on another continent.
It is unknown when he took his first victim but still as Mudgett he enrolled in the University of Michigan Medical School with the intent on making himself a more efficient killer. He graduated in 1884. While still in school he mastered the scheme of stealing bodies from the university laboratory and collected money from insurance policies he had taken out on them. Collecting insurance on his future victims became a steady source of income.
He moved to Chicago to to take advantage of his medical knowledge by pursuing a career in pharmaceuticals. He adopted his alias commonly referred to as H. H. Holmes and entered into ventures both legal and not. He made his money in real estate, business and murder. He started to work at a drugstore in Chicago and eventually became sole proprietor after the owner disappeared. Murder turned profitable as he started to sell the skeletons and organs of his victims to universities around the country.
He amassed great wealth and used it to purchase the property across the street from the drugstore and he started building a massive three story, block long hotel. There was an evil plan at unfolding. Holmes knew that Chicago would host the 1893 World's Fair just blocks from his location and he would have it completed by then. Each week he had a different construction crew so no one knew the true lay out of the hotel. The neighbors called it a castle but it would later be adjusted to the "Murder Castle". He put the finishing touch on the outside by naming it World's Fair Hotel.
There were gas lines running to each bedroom where he could asphyxiate them at whim. He also had a sound proof vault next to an office he had on premises where he could suffocate other victims. A hidden chute went from many of the rooms directly to the basement. There was a torture room in the basement complete with a stretching rack. The basement also had two giant furnaces and pits of acid.
The 1893 World's Fair offered him many victims with people from out of town looking for a place to stay. He continued his insurance scheme by having people sign life insurance policies as they checked in. Holmes collected insurance policies and sold the skeletons and organs of some victims.
A glass bending factory on the other side of town was also owned by Holmes although it was never used for that purpose. While not close to his hotel it was near an apartment he had rented for a mistress Minnie Williams whose personal belongings were found in the factory. Mudgett\Holmes had been married three times but never officially divorced any of them. Police also discovered that Holmes had owned and operated a Fruit and Grocery Store near there under the alias of Frank Wilde.
There is also evidence that Holmes may also have been the infamous Jack the Ripper. He was in London at the time trying to sell a skeleton to the local universities. He possessed the medical knowledge that the Ripper would have had. His handwriting was a near perfect match to the letters that the Ripper sent to the police.
It was his murder and insurance claim pattern that did him in. Holmes had come up with a plan where his longtime associate Benjamin Pitezel would fake his own death and Pitezel and his wife would collect the insurance and split it with Holmes. Holmes ended up killing Pitezel and collected the money himself. Later Holmes killed three of Pitezel's children and when he went to claim the money he was arrested. It was at that time that Chicago Police went to the Murder Castle in July 1895 and discovered the horrors there. The building burned to the ground on August 19, 1895. He was put to death by hanging on May 7, 1896.