As many as 170 people have been named over the years as suspects in the Jack the Ripper case [source: The Guardian]. Some have proven controversial, such as the "Jill the Ripper" scenario of Jack as a woman, painter Walter Sickert, author Lewis Carroll or heir to the throne Prince Albert Victor. Some conspiracy theories suggest that the entire royal family or the Freemasons were behind the killings.
Over the years, suspects have been painstakingly vetted by Ripperologists, and in some cases they've been exonerated. Take Michael Ostrog, for example. This Russian physician and convicted thief was a suspect since he was named (along with two other men) in the final report on the unsolved case, written by police commissioner Sir Neville Macnaughten in 1889 [source: Bardsley]. Ostrog hardly fit the bill, being a petty criminal and never suspected of any other murders, although he was committed several times to asylums. His unknown whereabouts during the murders kept him a viable candidate until author Phillip Sugden wrote in his 2002 book that Paris police documents show Ostrog was in their custody in France during the Ripper murders [source: Sugden].
Macnaughten also named another physician -- Montague John Druitt, who vanished after Kelly's murder at Miller Court. Druitt was found drowned in the Thames the following December, which fit Macnaughten's view that the killings ended due to the death or the incarceration of the murderer [source: Bardsley]. The third suspect named in the report is Aaron Kosminski. This man was insane and was committed to an asylum, where he died in 1919. Despite Macnaughten's description, he wasn't considered violent, however [source: Casebook].
It's possible Macnaughten had Kosminski confused with another man who was also a suspect -- Severin Klosowski (aka George Chapman). He was named in a 1903 press interview by a lead inspector on the case, Frederick George Abberline [source: Morrison]. He was the only named suspect who was a known serial murderer, having poisoned three of his wives. He kept late hours at night, had a regular job and was trained as a physician. He also moved to the United States and lived in New Jersey when the lone possible American Ripper victim was killed. But Klosowski used poison to kill, a vastly different M.O. from the Ripper's. He did, however, attack his first wife with a knife but was interrupted before he could harm her [source: Casebook].
Another investigator involved in the original case favored Dr. Francis J. Tumblety as a suspect. He was an American doctor who'd been arrested in November 1888 for indecency, posted bail and fled back to the U.S. [source: London Metropolitan Police]. Scotland Yard detectives traveled to America to investigate Tumblety but made no arrest.
Another probable suspect is Joseph Barnett. He was a fishmonger and would've known his way around a knife. And Barnett almost completely fits both the physical and psychological profiles of the killer. What's more, Barnett lived with the final canonical victim, Mary Jane Kelly, just before her murder and was in love with her. It's possible that her death was the culmination of his murderous rampages, which would explain why the murders ceased [source: Casebook].
Almost religiously, modern-day Ripperologists have pored over possible suspects. Their work illustrates the power the murders still hold. Find out about the legacy of Jack the Ripper on the next page.