The most infamous serial killer in history has reportedly been unmasked, 126 years later.
Jack The Ripper stalked the East End in 1888 and murdered at least five women.
According to various theories, he was a member of the Royal family, a former prime minister or painter Walter Sickert.
Now, the latest theorist has stepped forward, saying the murderer was none of these but in fact, a Polish immigrant named Aaron Kosminski who was later committed to an asylum, where he died.
Using a shawl of one of the Ripper's victims, Catherine Eddowes, DNA tests have shown Kosminski's blood is present, according to businessman and amateur sleuth Russell Edwards.
Mr Edwards bought the shawl at auction in 2007 and enlisted the help of Dr Jari Louhelainen, an expert in the forensic investigation of historic crime scenes.
Writing in The Mail On Sunday, Mr Edwards said he and Dr Louhelainen tested semen on the shawl against a DNA swab taken from a distant British descendant of Kosminski.
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He writes: "Amplifying and sequencing the DNA from the cells found on the shawl took months of painstaking, innovative work.
"By that point, my excitement had reached fever-pitch. And when the email finally arrived telling me Jari had found a perfect match, I was overwhelmed. Seven years after I bought the shawl, we had nailed Aaron Kosminski."
He adds: "Kosminski was not a member of the Royal Family, or an eminent surgeon or politician. Serial killers rarely are."
"Instead, he was a pathetic creature, a lunatic who achieved sexual satisfaction from slashing women to death in the most brutal manner. He died in Leavesden Asylum from gangrene at the age of 53, weighing just 7 stone.
"No doubt a slew of books and films will now emerge to speculate on his personality and motivation. I have no wish to do so.
"I wanted to provide real answers using scientific evidence, and I’m overwhelmed that 126 years on, I have solved the mystery."
Because of the age of the shawl, Dr Louhelainen used a method he called ‘vacuuming’, using a pipette filled with a special ‘buffering’ liquid that removed the genetic material in the cloth without damaging it.
Also writing in the Mail On Sunday, he said: "Now that it’s over, I’m excited and proud of what we’ve achieved, and satisfied that we have established, as far as we possibly can, that Aaron Kosminski is the culprit."
Kominski was committed to an asylum in 1891 and died there in 1919.
There is evidence that police at the time regarded Kosminski as the chief suspect.
In 2006, the Metropolitan Police's Crime Museum obtained a copy of the memoir of a senior officer in which Chief Inspector Donald Swanson, who was the original officer in charge of the Ripper investigation, had made handwritten notes.
The final words he wrote were: "Kosminski was the supsect."