Why Aaron Kosminski Is Jack The Ripper? – Celebrity
Sarah Oconnor
Updated on January 18, 2026
What happened to Aaron Kosminski?
In 1891, Aaron Kosminski was confined to the Colney Hatch Asylum. The five “canonical murders,” officially credited to Jack the Ripper, stopped soon after. Cambridge University has copies of Aaron Kosminski’s psychiatric records from the time he spent in the facility. According to the records, he heard auditory hallucinations that told him to do things. “He declares that he is guided and his movements altogether controlled by an instinct that informs his mind.” The documents also state that Kosminski grabbed a knife and threatened to slit his sister’s throat. It was clear to everyone, even his doctors, that he hated all women.
Aaron Kosminski was taken to “The Seaside Home, ” which is now believed to be a police convalescent home in Brighton used to interrogate suspects. However, police cannot continue to keep a suspect in custody unless charges are brought against them. Without the witness testimony from “the fellow Jew,” they could not prosecute and eventually hang Kosminski for being Jack the Ripper. Even though Kosminski was never put in jail, some would argue that a lifetime in an insane asylum would be equally terrible, if not worse. While living in the asylum, Kosminski lost a tremendous amount of weight. His mind slipped into dementia until he was not able to tell where he was and became unresponsive. Aaron Kosminski died in 1919 when he was 53 years old.
Jack the Ripper was thought to have had some level of knowledge in human anatomy, because he was very meticulous in the way that he dissected his victims and removed their organs. Detectives believed that this could not have been done unless he was a doctor or had some level of medical knowledge.
A shawl that belonged to Jack the Ripper ’s fourth victim, Catherine Eddowes, was purchased by a man named Russell Edwards in 2007. He was so determined to figure out the killer’s identity that he had the shawl tested for DNA in 2014. This genetic material was traced back to one of Aaron Kosminski’s living relatives. Edwards was also the author of a book called Naming Jack the Ripper, where he lays out his analysis of the case over decades of research.
However, there were claims that the scientist who analyzed the DNA, Jari Louhelainen, made a mistake in his analysis.
Barbers advertised with a pole containing a red stripe to signify that people could go there for the odd combination of bloodletting, dentistry, surgery, and haircuts.
Where did Jack the Ripper work?
He worked as a hairdresser in Whitechapel in the East End of London, where a series of murders ascribed to an unidentified figure nicknamed “Jack the Ripper” were committed in 1888. From 1891, Kosminski was institutionalised after he threatened a woman with a knife.
Nationality. Polish. Occupation. Barber, hairdresser. Known for. Jack the Ripper suspect. Aaron Kosminski (born Aron Mordke Kozmiński; 11 September 1865 – 24 March 1919) was a Polish barber and hairdresser, and suspect in the Jack the Ripper case. Kosminski was a Polish Jew who emigrated from Congress Poland to England in the 1880s.
Macnaghten stated that there were strong reasons for suspecting “Kosminski” because he “had a great hatred of women … with strong homicidal tendencies”. In 1910, Assistant Commissioner Sir Robert Anderson claimed in his memoirs The Lighter Side of My Official Life that the Ripper was a “low-class Polish Jew”.
Macnaghten’s notes say that “Kosminski” indulged in “solitary vices”, and in his memoirs Anderson wrote of his suspect’s “unmentionable vices”, both of which may match the claim in the case notes that Aaron Kosminski committed “self-abuse”.
Colney Hatch Lunatic Asylum, North London. Kosminski was an inmate from 1891 to 1894. Aaron Kosminski was born in Kłodawa in Congress Poland, then part of the Russian Empire. His parents were Abram Józef Kozmiński, a tailor, and his wife Golda née Lubnowska.
He was first held at Colney Hatch Lunatic Asylum, and then transferred to the Leavesden Asylum . Police officials from the time of the murders named one of their suspects as “Kosminski” (the forename was not given), and described him as a Polish Jew in an insane asylum.
In 2007, he bought a shawl which he believed to have been left at a murder scene and gave it to biochemist Jari Louhelainen to test for DNA.
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Why was Kosminski identified as Jack the Ripper?
Assistant Commissioner Anderson also made claims that Kosminski was identified as Jack the Ripper by a witness who was unable to help a prosecution because he was unable to testify against a fellow Jew, although this was never verified.
Believed to have been born in Russia in 1865, Aron Mordke Kozminski – known later as Aaron Kosminski – was a Polish Jew who emigrated with his sisters when he was just 15 years old. Initially, he moved to Germany before eventually travelling to London, England where he took up residence in the slums of Whitechapel.
In addition, the name Kosminski also appeared in the memoirs of the Assistant Commissioner Sir Robert Anderson in 1910, based on Kosminski ’s violent outburst with a knife that led to his arrest and detainment in the workhouse (and subsequently Colney Hatch Asylum).
He was just 53 years old when he died of gangrene in February 1919.
Aaron Kosminki is perhaps one of the most well-known Jack the Ripper suspects, in part thanks to the recent DNA analysis and investigation of a shawl that allegedly belonged to the fourth Ripper victim, Catherine Eddowes.
Although not officially named as a suspect by police investigating the Jack the Ripper killings, the name Kosminski has cropped up multiple times over the years. Firstly, Chief inspector Swanson was also a firm believer that Kosminski was a prime Jack the Ripper suspect.
Did Jack the Ripper have mitochondrial DNA?
The international press has been abuzz with news that Jack the Ripper may have been identified based on mitochondrial DNA. But there are a number of skeptics out there, and they have some very good reasons for doubting that the findings are going to stick:
Kosminski was a decent suspect but not, as Ripperologist Marilyn Bardsley points out, the best one: “The only bit of evidence amassed against Kosminski was a reputedly positive identification by one of the eyewitnesses, mostly likely Joseph Lawende ….