Today, we mourn the passing of Herman Webster Mudgett, better known to history as H.H. Holmes. At the age of 34, Holmes died on May 7, 1896. Best known as one of America's first serial killers, Holmes was born in 1859 in New Hampshire and received an education in medicine and pharmacy. During the World's Fair in Chicago in 1893, Holmes constructed the infamous "Murder Castle" - a three-story building complete with a concealed chamber, soundproof rooms and hidden passage ways. Holmes confessed to 27 murders; while he is believed to have committed far more, only nine of his victims were identified. His trial was highly publicized, and he was sentenced to death by hanging. He was executed in May of 1896. Holmes will be remembered as one of America's most notorious criminals, responsible for one of the most infamous murders in history. He will be deeply missed, but also remembered for his heinous acts.