When you meet Aaron Kosminski, you step into one of history’s most chilling mysteries. The infamous serial killer known as Jack the Ripper has haunted the public imagination since the Victorian era, brutally murdering and dismembering at least five sex workers in London’s Whitechapel district between 1888 and 1891. Despite dozens of eyewitnesses claiming to have seen the killer fleeing the scenes, he slipped through the grasp of the police and the case went cold.
10 The DNA Evidence
A shawl belonging to Catherine Eddowes, the fourth victim, was bought by Russell Edwards in 2007. Determined to uncover the killer’s identity, Edwards commissioned DNA testing in 2014. The genetic material retrieved was traced back to a living relative of Aaron Kosminski. Edwards also authored Naming Jack the Ripper, outlining his decades‑long research.
Critics, however, argued that the scientist Jari Louhelainen may have erred in his analysis. The DNA evidence was not widely accepted until it underwent peer review, appearing in the 2019 issue of The Journal of Forensic Sciences. The study confirmed the DNA matched Kosminski’s lineage, yet skeptics questioned whether a century‑old shawl could avoid contamination. The journal explained that mitochondrial DNA (mtDNA) can only exclude suspects, not definitively identify them. Moreover, the shawl never appeared in contemporary police reports, and its provenance remains uncertain—did it truly belong to Eddowes? Consequently, the DNA findings have added more debate than resolution.
9 Kosminski Had a Dark and Tragic Backstory
Every serial killer tends to have a grim origin story, and Aaron Kosminski is no exception. Born into a Jewish family in Poland, he witnessed the 1881 Warsaw Pogrom—a violent riot that erupted after Tsar Alexander II’s assassination. Sixteen‑year‑old Kosminski saw brutal slaughter, prompting his family to flee first to Germany and later to England. His father, a tailor in Poland, is believed to have worked either in a hospital or as a barber, possibly juggling both trades to support the family.
Polish refugees poured into London’s East End, swelling the overcrowded Whitechapel district. Unemployment ran rampant, crime flourished, and many women turned to prostitution to survive. Growing up amid such squalor and desperation could hardly have been an ideal launchpad for a respectable adult life.
8 He Had Anatomical Knowledge
Detectives long suspected that Jack the Ripper possessed a working knowledge of human anatomy, given the precise way he dissected victims and removed organs. They believed only a doctor or someone with medical training could execute such meticulous mutilations.
Aaron Kosminski was a professional barber, and his father had hospital experience. Historically, barbers served as “barber‑surgeons,” offering bloodletting, dentistry, surgery, and haircuts—all signaled by the iconic red‑striped pole. By Kosminski’s era, the formal barber‑surgeon tradition had faded, yet his trade would still require a keen awareness of neck arteries and the handling of a razor‑sharp blade—tools capable of cutting flesh. It’s plausible he acquired additional medical knowledge from his father’s hospital work.
7 He Had a Deep Hatred Towards Women
Modern serial‑killer research often reveals a profound animus toward women, usually stemming from repeated rejection or a troubled maternal relationship. Jack the Ripper’s victims were all sex workers, and the grotesque mutilations suggest an irrational rage directed at women he never personally knew.
Kosminski was 23 when the first murder occurred, never married, and reportedly struggled socially with women. Chief Constable Meville Macnaghten of Scotland Yard noted that Kosminski harbored a “great hatred of women, especially of the prostitute class, & had strong homicidal tendencies.” This observation aligns with the broader psychological profile of many killers who target women.
6 The Clue on Goulston Street
On September 30, 1888, Elizabeth Stride and Catherine Eddowes were slain. A fragment of Eddowes’ apron was recovered, and a chalk message appeared on a wall near Goulston Street: “The Jews are the men that will not be blamed for nothing.” The word “Jews” was misspelled “Juwes,” and the double negative hints at a non‑native English speaker.
The clue sparked endless debate. Some argued it was an attempt to blame Jewish people; others believed it was a false lead. Second Assistant Commissioner Sir Robert Anderson was convinced the killer was Jewish, writing in his memoir The Lighter Side of My Official Life that Aaron Kosminski, a Polish Jew, was “safely caged in an asylum.” Anderson’s conviction reinforced the theory that the message pointed to Kosminski.
5 Physical Description
Witness accounts of Jack the Ripper vary wildly. Some described a tall, middle‑aged gentleman with a curly moustache; others recalled a short, stocky, clean‑shaven man between 25 and 30 years old. The inconsistency makes it impossible to pinpoint his exact look.
Constable Meville Macnaghten’s “Macnaghten Memoranda” recorded that a police officer spotted a suspect on the night of Catherine Eddowes’ murder who strongly resembled Aaron Kosminski. Unfortunately, many of those police files were destroyed during the London Blitz, preventing modern investigators from examining the original descriptions.
4 Jack the Ripper Had a Foreign Accent
On September 8, 1888, witness Elizabeth Long reported seeing Annie Chapman converse with a mysterious man shortly before her murder. The man, described as “shabby, genteel,” wore a dark coat and deerstalker hat. Long heard him ask, “Will you?” as Chapman agreed to a transaction. His voice carried a distinct foreign accent.
While Kosminski was not the only suspect of non‑English origin, this accent, combined with the misspelled Goulston Street message, strengthens the argument that the killer was an immigrant rather than a native Londoner.
3 Kosminski Was Put Into an Insane Asylum
In 1891, Aaron Kosminski was committed to Colney Hatch Asylum. The canonical five murders ceased shortly thereafter. Cambridge University holds copies of his psychiatric records, which detail auditory hallucinations urging him to act. One entry notes he threatened to slit his sister’s throat with a knife, confirming a deep‑seated hatred toward women.
Modern psychiatrists diagnose Kosminski with paranoid schizophrenia. Some argue he was more self‑harm‑oriented, refusing food for fear of poisoning and subsisting on gutter scraps. Cambridge’s analysis clarifies that references to “self‑harm” actually described frequent masturbation rather than violence toward other inmates. Nonetheless, his documented aggression toward women persisted.
2 A Jewish Witness Saw His Face
Sir Robert Anderson, the second Assistant Commissioner of the Metropolitan Police, later penned an autobiography asserting his conviction that Aaron Kosminski was Jack the Ripper. Chief Inspector Donald Sutherland Swanson possessed a copy of Anderson’s book, annotated with marginal notes revealing additional details.
According to Swanson’s notes, a Jewish witness had seen the killer’s face but declined to testify, fearing the moral burden of contributing to a hanging. Anderson recorded, “The suspect was also a Jew … and because his evidence would convict the suspect and witness would be the means of murderer being hanged which he did not wish to be left on his mind…” Swanson added, “The suspect was Kosminski.” This alleged eyewitness testimony, though never presented in court, bolstered the case against Kosminski.
1 They Almost Caught Him
Aaron Kosminski was taken to “The Seaside Home,” believed to be a police convalescent facility in Brighton used for interrogating suspects. However, without the testimony of the aforementioned Jewish witness, authorities could not bring formal charges, and thus could not legally detain him for execution.
Although Kosminski never faced a courtroom, his confinement in an asylum effectively removed him from society. While there, he lost significant weight, slipped into dementia, and eventually became unresponsive. He died in 1919 at the age of 53.
Even though Sir Robert Anderson and many Scotland Yard investigators were convinced of Kosminski’s guilt, the lack of a formal conviction left the case perpetually open, fueling ongoing debate among true‑crime enthusiasts.
About The Author: Shannon Quinn writes things. Follow her on Twitter @ShannQ.