Herman Mudgett, preferring to be called H.H. Holmes, was responsible for the deaths of 150-200 people between the late 1880's to the mid 1890's. A respectable and attractive young man, Holmes first worked as a prescription clerk at a drug store in Chicago. Scamming and falsely marketing various "cure all" medicines, Holmes was able to purchase a large plot of land in which would become known as the Holmes Castle. With 100 rooms in the huge mansion, Holmes constructed "false partitions, stairways leading nowhere, long dark corridors, trap doors, and secret passageways." In most rooms, there were gas pipes installed with fake valves that would asphyxiate his victims without their knowledge. Also found in the castle were tubs of acid to burn the flesh of his victims as well as a medieval torture rack used to stretch bodies to twice their normal size. There was also an electronic bell that would ring every time a door would open to let Holmes know of any potential escape. Holmes preferred modus operandi was to gas his victims to death in a locked room and then add fire which would torch the flesh of the victims. What would end Holmes reign of terror was the murder of Benjamin Pitezel, a business partner of Holmes, who he killed and dumped in Philadelphia sometime in September 1894. In 1895, Holmes was found guilty of the slaughter of 27 people and sentenced to death. Holmes was subjected to fifteen minutes of unbearable pain when the gallows failed to execute him immediately. He was thirty-six years old. The Guinness Book Of World Records named him "the most prolific murderer in recent criminal history".