Herman Webster Mudgett (1861-1896) graduated from the University of Michigan Medical School in 1884 and moved to Chicago to practice pharmacy. He also began to engage in a number of shady business, real estate, and promotional deals under the name "Dr. H. H. Holmes." His greed would prove to be the impetus behind one of the bloodiest serial killers in history.

Mudgett researched his dreadful pastime at his illustrious medical school. An expert in acid burns, he boosted his student allowance by body snatching. He supplied countless cadavers to medical schools, selling them for $25 to $50 whenever he needed quick cash.

He would also steal corpses, render them unrecognizable, then collect on the life insurance policies he had previously taken out under fictitious names. Mudgett got away with several of these frauds before a night watchman caught him removing a female corpse. He fled the University of Michigan.

After leaving Ann Arbor, Mudgett turned up in Chicago where he turned into Dr. H.H. Holmes. He opened a respectable pharmacy without a hint of scandal. So successful was he, that in 1890 he bought a vacant lot on Chicago's south side 63rd Street and set about building a grand boarding house.

The house, or "The Castle" as it was called, was completed just in time for the 1893 World's Fair. It contained over 100 rooms. The first floor was occupied by shops and boutiques, and the third floor housed his personal offices and living quarters. The middle floor would prove to be one of the most terrible real-life houses of horror imaginable.

The mansion's middle floor was filled with doors that opened to brick walls, stairways to nowhere, an elevator without a shaft and a shaft without an elevator.

There was an airtight and soundproof vault, torture chambers, dissecting tables, a crematorium, chemical vats, quicklime pits, and human-sized greased chutes leading from the living quarters to the cellar.

Peepholes were everywhere. The bedrooms were equipped with asphyxiating gas pipes connected to a control panel in Dr. Holmes' closet, so he could murder his guests at will.

Dr. Holmes was also said to have an "elasticity determinator," a machine he claimed could stretch experimental subjects to twice their normal length in order to produce a race of giants. Those who viewed it (and lived) said it appeared to be a medieval torture rack.

Holmes, a charismatic and charming doctor, had little trouble collecting his victims. He repeatedly advertised his "boardinghouse" and attracted many unassuming young women. Repeatedly they willingly walked into his "Castle," but not out. The poor girls would be tortured until they delivered all their possessions to him, then murdered. Their bodies would be thrown down a chute into vats of acid and lime, then cremated.

It was not his need to murder, necessarily, that would be Holmes' undoing. Instead, it was his greed.

One of Holmes's partners, Ben Pitezel, took out a life-insurance policy on himself for $10,000 with Holmes as the beneficiary. They concocted a plan where Pitezel would "disappear" and Holmes would produce a false corpse, identify it as Pitezel's, and share the payoff with Pitezel's family. It was his old trick from Medical School.

Pitezel disappeared on schedule and Holmes collected the money. But someone tipped off the police about the scheme, and Holmes fled with the eldest Pitezel daughter.

Telling Mrs. Pitezel that her husband was hiding in a nearby city, Holmes convinced her to follow him. She believed the lie, and for months they moved separately and together around the United States and Canada, taking the other Pitezel children with them.

During the group's wanderings Ben Pitezel's body was discovered in Chicago and Holmes was officially charged with murder. The police searched Holmes 63rd street property and discovered it for the "Horror Castle" that it was.

Meanwhile, still on the run, Holmes murdered three of the five Pitezel children and hid their bodies. The bodies of Alice and Nellie Pitezel were found in a cellar in Toronto and Howard Pitezel's remains were found near Indianapolis. The Pitezel girls had been stuffed in a trunk and gassed; Howard was poisoned, burned and then dismembered and buried.

Aided by Mrs. Pitezel, the police finally captured Holmes. He was arrested in Boston in 1894 and extradited to Philadelphia for Mr. Pitezel's murder.

Ultimately, Dr. Holmes was hanged for one murder in Philadelphia, but he might have committed hundreds more in Chicago. Authorities suspected as many as 50 visitors to the World's Fair in 1893 made a tragic choice of lodging and stayed at Dr. Holmes' boardinghouse.

In addition, as many as 200 young ladies (the number Holmes confessed to murdering) who answered his continual string of newspaper ads disappeared forever after entering the three-story slaughterhouse.

Investigators could neither confirm nor disprove Holmes' confession, because the recognizably human remains found in the iron tanks of acid and lime, not to mention the crematory, could not be differentiated.

Holmes was finally hanged on May 7, 1896. Afraid scientists might dig up his corpse to study his brain, Dr. Holmes had left specific instructions for his burial. His body was laid in a pine box, and the box was then filled with cement. The coffin was buried 10 feet deep in a suburban Philadelphia cemetery, then covered with another thick layer of cement.

So ended the life of Herman Mudgett, a.k.a. Dr. H. H. Holmes, one of the nation's worst (though oddly least known) serial killers.