David Cohen

Could the identity of one of history’s most notorious killers have remained a secret for more than a century because of a case of mistaken identity? If the theory that pins the Canonical Five murders on David Cohen is correct, then that’s exactly what happened. But how could the police have gotten it so wrong?

Who Was David Cohen?

The theory that was put together, pinning the chilling Whitechapel murders on one David Cohen, claims that this name was actually the ‘John Doe’ identity given to him at the time. He was taken in when found stumbling through the streets of East End London in December of 1888, a few short months after the autumn of terror. It is claimed that Cohen’s real name was Nathan Kaminsky, a Polish Jew that matched the description of the wanted man known as ‘Leather Apron’, who would later form the pseudonym of Jack the Ripper.

Kaminsky/ Kosminski

Cohen, born in 1865, was not actually named as a potential suspect in the Jack the Ripper case until Martin Fido’s book ‘The Crimes, Detection and Death of Jack the Ripper’ was published in 1987 – almost 100 years later. The book detailed Cohen’s alleged erratic and violent behaviour, which made him a good fit for the killers' profile.

As per an 1895 article by Sir Robert Anderson, who was the Assistant Commissioner CID at Scotland Yard at the time of the murders, it becomes apparent that the killer was in fact identified by a witness. The witness, however, refused to come forward in an official capacity, leading Anderson to write “the only person who had ever had a good view of the murderer unhesitatingly identified the suspect the instant he was confronted with him; but he refused to give evidence against him."

Later, in his 1910 book ‘The Lighter Side of My Official Life’, Anderson published a memoir hand-written by ex-Superintendent Donald S. Swanson, in which he named Aaron Kosminski as the suspect who matched the description of a Polish Jew. The passage reads: “The suspect had , at the Seaside Home where he had been sent by us with difficulty in order to subject him to identification, and he knew he was identified.

“On suspect's return to his brother's house in Whitechapel he was watched by the police (City CID) by day & night. In time, the suspect with his hands tied behind his back, he was sent to Stephney Workhouse and then to Colney Hatch and died shortly afterwards - Kosminski was the suspect – DSS."

Mistaken Identity

There is one major problem with the timing of the events that took place however, and that is the fact that Kosminski did not die until 24 March 1919. So, how exactly could he have been named as the suspect who died shortly after arriving at Colney Hatch in Anderson’s book which was published nine years prior? The only explanation is that Swanson had named the wrong man.

Having conducted an investigation, Fido could not find any entry under the name Kosminski for patients admitted to Colney Hatch asylum in spring 1889. In fact, Kosminksi would not arrive at the asylum until 1891, almost two years after these events supposedly took place.

What Fido did find, however, was a patient admitted under the name of ‘David Cohen’, which was a generic ‘John Doe’ name used for Jews in the East End without any known identity or address.

Cohen was transferred to Colney Hatch after displaying violent behaviour that put both himself and others at risk, resulting in the need for him to be placed in restraints. Some of the notes about his time at Colney state that Cohen had to be force-fed food, wear a ‘strong dress’ because his tendency to tear his clothes off and was just generally regarded as being a destructive individual. Cohen was reported to have died in October 1889 at Colney Hatch of ‘exhaustion of mania’ after several days confined to his bed.

Was David Cohen’s Real Name Nathan Kaminsky?

Nathan Kaminsky is believed to have been David cohen’s real name. While the timings relating to Cohen/Kaminsky certainly match up with Anderson’s memoirs, how does Fido link Nathan Kaminsky to the apparent alias? Again, the timings match up in this theory; the last we know about Kaminsky is that he was released from Whitechapel Workhouse Infirmary in May 1889, having been cured of syphilis (which would have been a potential sign of sexual contact with prostitutes).

In addition to this, Kaminsky was known to have lived in a location central to the Ripper murders, in Black Lion Yard – this, added to his possible meetings with prostitutes, matches Sir Robert Anderson’s own description of the suspect in his 1895 article: "One did not need to be a Sherlock Holmes to discover that the criminal was a sexual maniac of a virulent type; that he was living in the immediate vicinity of the scenes of the murders.”

But What About the Witness?

The witness, who is likely to have been Joseph Lawende who was named during the investigation of the murder of Catherine Eddowes, is believed to have correctly identified Kaminsky – not Kosminski – adding more weight to the theory that the name was simply mixed up when Swanson named the suspect in his book.

Was David Cohen / Nathan Kaminsky the real Jack the Ripper?

Does this mean, then, that even if Kosminski was mistakenly named as the suspect in the memoirs, that Kaminsky was known to have been Jack the Ripper all along? Is the fact that Lawende was unwilling to come forward the only reason as to why Kaminsky is not unequivocally known to be the man behind the Jack the Ripper killings?

We will likely never know the answer to those questions, but you can make your own mind up by taking a Jack the Ripper tour with one of our expert Ripperologists. Tours run daily, seven days a week, starting from outside exit three of Aldgate East Station in London. You can book online to secure your spot on one of London’s best tours today, which has been voted number one by Trip Advisor.


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The Jack the Ripper Casebook