Died: October 1889 of "exhaustion of mania" at Colney Hatch asylum
Occupation: Tailor (?)
First suspected: First suggested in Martin Fido's The Crimes, Detection and Death of Jack the Ripper (1987)
Description: Brown hair, brown eyes, brown-bearded or unshaven
The "David Cohen" suspect is an expanded and revised version of what is known as the "Polish Jew theory", which in turn is originating from three primary sources:
According to these documents, we here have a poor Polish Jew, living in Whitechapel and who had "homocidal tendensies and a great hatred of women", and was confined to a lunatic asylum at the right time for the murders to stop and died shortly afterwards.
As a result of Swanson and Macnaghten naming the suspect, this led to Aaron Kosminski being the most popular "Polish Jew suspect" during recent years of Ripper studies. But research has since shown, that Kosminski - a former hairdresser - was a harmless imbecill, whose guiding instincts told him not to accept food from others or to take a bath. He picked up food from the gutters and refused to work. He had once threatened his sister with a knife, but he was neither suicidal or dangerous. And more importantly: he wasn't admitted to Colney Hatch asylum until February 1891 and didn't die until 1919! Apart from Macnaghten and Swanson identifying him by name, Aaron Kosminski didn't seem to fit the Polish Jew brought in by the police, considering the time lapses and discrepancies in character.
Fido, who originally set out to find someone called Kosminski - and who was supposed to have entered a lunatic asylum in the spring of 1889 (according to Macnaghten's account) - couldn't find him. Instead David Cohen appeared. In December 1888 a young and confused Polish Jew, found rambling on the streets and speaking little but Yiddish, was brought in by the police to the Leman station. Since he was uncommunicative, it was decided that he was unable to care for himself and that he should be taken to the parish workhouse. Then he suddenly became violent and had to be brought in under restraint. Since he didn't give them his name or adress, and noone recognized him, he was registered at the Infirmary as "David Cohen", which supposedly was used as a "John Doe" for East End Jew's without known identity, adress and next-of-kin.
In the Infirmary Cohen proved too dangerous for the other patients (and himself) and was therefore transfered to Colney Hatch, once again under restraint. There he had to remain under constant observation due to his violent tendensies; he was rambling and described as "spiteful and mischievous", he spat out food, had to be force-fead, tore down a lead pipe and wire window-guard in the yard, he was destructive, kicked passers-by and had to wear a "strong dress" in order not to tear his own clothes into pieces. Today he would most likely have been diagnosed as a paranoid schizophrenic. In October 1889 he was confined to his bed in the asylum and a few days later he died.
If this was Jack the Ripper, then how does Kosminski fit the David Cohen connection? Throughout the Ripper investigation the police had been seeking for a dangerous character, called "Leather Apron" (before the name "Jack the Ripper" had been established) who'd attacked and threatened prostitutes. A man named John Pizer had early on been accused of being identical with him, but was later cleared from suspicion and released. "Leather Apron" was one of many Jews from the poorest class connected to the "sweating trade" as a bootmaker or tailor, and he was supposed to have lived near Buck's Row (where Polly Nichols was killed).
Fido's research pointed towards a Polish Jew called Nathan Kaminsky, who proved a suitable candidate as "Leather Apron" and who lived in Black Lion Yard, right in the centre of the Ripper murders. In March 1888 he had been diagnosed as syphilitic at the Whitechapel Workhouse Infirmary (indicating that he would have been in sexual contact with prostitutes), wherefrom he was released and cured from his illness in May the same year. After that he disappears from the face of the Earth and no further records can be found of his whereabouts.
Fido argues that the dangerous schizophrenic "David Cohen" and the elusive Nathan Kaminsky actually are one and the same, and that his name was changed to David Cohen by the police, since they didn't know his identity or didn't bother to spell his name correctly, due to over-crowding and language difficulties. Then Macnaghten and Swanson confused the imbecill Aaron Kosminski with the "raving lunatic" David Cohen. There is no reason to doubt that Aaron Kosminski was mentally ill, taken into custody and then to his brother's house (and finally admitted to Colney Hatch), but he was neither dangerous or kept under restraint, and it didn't happen in 1888 or 1889.
The theory is, that the witness confrontation referred to by Anderson and Swanson (where the witness - probably Lawende - had encountered the possible suspect in connection with the murder of Catherine Eddowes) actually involved David Cohen/Kaminsky and not Kosminski, and that Macnaghten and Swanson mixed them up when they named the suspect. Thus, the timing and the differences in character could be explained. Nevertheless, while some claim the David Cohen theory and the Kaminsky/Kosminski confusion to be quite far-fetched and unnecessary complicated or abstract, others regard it as one of the more seriously researched and ground-breaking works to date.
Reasons for suspicion: "David Cohen" is the only insane Polish Jew who was committed to an asylum at the right time for the murders to stop - and the only registered lunatic pauper admitted to Colney Hatch between 1888-1890 who fits the extremely violent suspect described by Anderson, Macnaghten and Swanson. He also - in contrast to Aaron Kosminski - died shortly after the canonical Ripper murders ceased.
Problems with candidacy: The "name confusion" connected to Kosminski as well as the alleged link to Nathan Kaminsky or "Leather Apron" remains circumstancial and not proven. Furthermore, statements made by Robert Anderson in 1889 and Abberline in 1903, indicating that they had failed to catch or identify Jack the Ripper, seriously challenges the notion that the killer's identity was known to the police.-- Our thanks to Glenn L. Andersson for compiling this page.