For more than a century, the name Jack the Ripper has stood for one of the most infamous unsolved crime sprees in history. The five murders committed in London’s Whitechapel district between August and November 1888 have produced endless speculation, but the killer’s true identity has never been legally established. The most compelling suspect to emerge in recent decades is Aaron Kosminski, a Polish barber whose name was linked to the case through a police memo and later through contested DNA evidence. Yet even the strongest theory remains unproven, and the case file officially remains open.
Kosminski was born Aron Mordke Kozmiński in 1865 in Kłodawa, Congress Poland. He moved to London at the age of 15 and lived with his sisters in the Whitechapel area, working as a barber. In 1891 he was admitted to Colney Hatch Lunatic Asylum with a diagnosis of paranoid schizophrenia, where he was described as “harmless.” He died in a London mental institution on March 24, 1919. It was only in 1987 that researcher Martin Fido identified Kosminski as the person referenced in police marginalia, giving a full name to an otherwise vague suspect.
Modern forensic attention has centred on a silk shawl allegedly found near the body of victim Catherine Eddowes. In 2014, historian Russell Edwards claimed that DNA from semen and blood on the shawl matched a living descendant of Kosminski, a conclusion supported by a 2019 BBC documentary. However, the scientific community has not reached a consensus; critics point to the shawl’s questionable chain of custody and call the evidence insufficient. The case remains as contested as it is celebrated.
Who Was Jack the Ripper?
| Case name | Whitechapel Murders / Jack the Ripper |
| Active period | August – November 1888 |
| Confirmed victims | 5 canonical victims |
| Identity status | Unidentified – leading suspect Aaron Kosminski (DNA evidence inconclusive) |
- The killer’s identity remains officially unknown; Aaron Kosminski is the most cited suspect following the 2014 DNA analysis.
- The nickname “Jack the Ripper” originated from the “Dear Boss” letter, now widely believed to be a journalist hoax.
- The killer was never caught due to limited forensic science, jurisdictional ambiguity, and potential witness intimidation.
- No confirmed death date exists for Jack the Ripper because his identity is unknown.
- Kosminski was a Polish barber who lived in Whitechapel and was later institutionalised.
- Modern DNA evidence linking Kosminski to the Eddowes shawl is contested by many scientists.
| Attribute | Details |
|---|---|
| Number of canonical victims | 5 (Mary Ann Nichols, Annie Chapman, Elizabeth Stride, Catherine Eddowes, Mary Jane Kelly) |
| Murder method | Jugular slashing, abdominal mutilation, organ removal |
| Known letters | Over 300; only “Dear Boss” and “From Hell” are considered potentially genuine |
| Primary suspects | Aaron Kosminski, Montague John Druitt, Prince Albert Victor (speculative) |
| Mortality if Kosminski | Died 1919 in a mental asylum |
| Mortality if Druitt | Died 1888 (suicide) shortly after last murder |
| First police mention of Kosminski | 1894 memo by Sir Melville Macnaghten |
| DNA test year | 2014 (Russell Edwards) |
Why Was Jack the Ripper Called Jack the Ripper?
The name “Jack the Ripper” first appeared in a letter addressed to the Central News Agency dated September 27, 1888. The writer called himself “Jack the Ripper” and taunted the police. This letter became known as the “Dear Boss” letter. Authorities at the time believed it might be a hoax, most likely written by a journalist to sensationalise the story. Hundreds of similar letters followed, but only the “Dear Boss” and the “From Hell” letter (received in October 1888) are treated by experts as possibly genuine. The original documents are held by The National Archives (UK).
The Dear Boss Letter
The letter was written in red ink and signed “Jack the Ripper.” It promised to “clip the lady’s ears off.” After the double murder of Elizabeth Stride and Catherine Eddowes, another letter claiming to be from the killer included a piece of Eddowes’s apron. Many historians doubt the authenticity of these letters, noting that the name “Jack the Ripper” seems too theatrical for a real killer.
The “Dear Boss” letter is the sole origin of the name “Jack the Ripper.” If the letter is a hoax, the killer himself never used or acknowledged the nickname.
Why Was Jack the Ripper Never Caught?
Limited Forensic Science
In 1888, fingerprinting did not yet exist, DNA analysis was unthinkable, and crime scene preservation was rudimentary. Officers often moved or disturbed evidence. Neighbourhood patrols were sparse, and the dark, narrow streets of Whitechapel made it easy for a killer to escape unseen.
Jurisdictional Confusion
The murders fell across two police districts. The Metropolitan Police and the City of London Police each ran separate investigations. Communication was poor, and both forces later blamed the other for missed chances. No unified task force was created until after the last murder.
Witness Intimidation
The murders occurred in an area rife with poverty, anti-immigrant sentiment, and fear of the police. Many potential witnesses were reluctant to come forward. According to some records, a witness placed Kosminski near one murder scene but was unwilling to swear to the identification under oath.
Some online sources claim that Jack the Ripper’s name is definitively Aaron Kosminski. This is not supported by legal or scientific consensus. The case remains unsolved, and claims of a “case closed” are premature.
When Did Jack the Ripper Die?
Because the identity of the killer is unknown, there is no confirmed date of death. Each suspect theory carries its own mortality.
If Aaron Kosminski Was the Ripper
Kosminski died of paranoid schizophrenia-related complications on March 24, 1919, at the Leavesden Asylum in London. He had been institutionalised since 1891.
If Montague John Druitt Was the Ripper
Druitt, a barrister and teacher, died by suicide in December 1888, shortly after the final canonical murder. His body was found in the Thames.
Other Suspects
Prince Albert Victor, grandson of Queen Victoria, is sometimes named, but there is no credible evidence linking him to the murders. The question of when Jack the Ripper died can only be answered based on which suspect is accepted.
If you are researching the case, the most reliable primary documents—including police reports and letters—are publicly available through Casebook: Jack the Ripper, a site that catalogs original sources.
What Was the Timeline of the Whitechapel Murders?
- August 31, 1888: Mary Ann Nichols murdered in Buck’s Row.
- September 8, 1888: Annie Chapman murdered in Hanbury Street.
- September 27, 1888: “Dear Boss” letter received by the Central News Agency.
- September 30, 1888: Elizabeth Stride and Catherine Eddowes murdered (the “double event”).
- October 16, 1888: “From Hell” letter received by George Lusk, chairman of the Whitechapel Vigilance Committee.
- November 9, 1888: Mary Jane Kelly murdered in Miller’s Court – the most brutal of the five.
- February 13, 1891: Frances Coles murdered; some link her to the Ripper, but she is not part of the canonical five.
- 1919: Aaron Kosminski dies in Leavesden Asylum.
What Do We Know for Certain About Jack the Ripper?
| Established information | Information that remains unclear |
|---|---|
| Five canonical murders occurred in Whitechapel, 1888. | The killer’s true identity. |
| The killer was never identified or caught by police. | Whether James Maybrick, Montague Druitt, or Prince Albert Victor were the Ripper (no direct evidence). |
| The same method (jugular cutting, abdominal mutilation) linked the five killings. | The authenticity of most “Jack the Ripper” letters. |
| Police at the time considered a Polish Jewish suspect (Kosminski) plausible. | The 2014 DNA evidence linking Aaron Kosminski is contested. |
What Was the Social and Historical Context of the Murders?
The Whitechapel murders took place in one of the poorest districts of Victorian London. Overcrowding, low wages, and a large immigrant population—especially Eastern European Jews—created a tense atmosphere. Anti-immigrant sentiment was high, and some newspapers fuelled prejudice by describing the killer as a “foreigner.”
Police investigation methods were primitive by modern standards. There were no crime labs, no centralised databases, and no reliable means of tracking suspects across district boundaries. The lack of forensic tools meant that even when a suspect was named, proving guilt was extremely difficult.
The case quickly became a cultural phenomenon. Sensationalised newspaper coverage, the gruesome murders, and the mystery of the killer’s identity captured the public imagination. Hundreds of theories, films, and books followed, many based on flimsy evidence. For a look at another high-profile unsolved biography (though with a different outcome), read our coverage of Erik Menendez – 2025 Parole Denial and Full Biography.
What Are the Key Sources and Quotes in the Case?
“Sorry to hear I have given the police so much trouble. I shall have some more by and by.”
— From the “Dear Boss” letter, September 1888, reproduced by Wikipedia: Jack the Ripper
The original police reports, letters, and inquest documents are preserved at The National Archives (UK). The most comprehensive historical account is “The Complete Jack the Ripper” by Donald Rumbelow. Criminologist Professor David Wilson has stated that Kosminski is the “most likely” suspect, though he acknowledges the evidence is circumstantial. Britannica: Jack the Ripper provides a well-cited summary of the case and its main suspects.
What Is the Bottom Line on Jack the Ripper’s Identity?
After 137 years, no single suspect has been proven guilty. Aaron Kosminski is the strongest candidate based on police notes, proximity to the crimes, and a contested DNA result. Yet the scientific and historical communities have not reached a verdict. The case remains one of the world’s most famous unsolved mysteries. For a deeper dive into the evidence and suspects, see Jack Ripper – Real Name, Identity, and Why He Was Never Caught.
Frequently Asked Questions About Jack the Ripper
How many women did Jack the Ripper kill?
Five women are considered the “canonical five” victims, all killed between August and November 1888.
What were the Jack the Ripper letters?
Hundreds of letters claiming to be from the killer were sent to police. The “Dear Boss” letter coined the name “Jack the Ripper.” Most are believed to be hoaxes.
Is there any DNA evidence linking Aaron Kosminski?
Yes, a 2014 analysis of a shawl found near Catherine Eddowes claimed a DNA match with a Kosminski descendant, but many scientists dispute the provenance and reliability.
Who are the other main suspects?
Montague John Druitt (a barrister who committed suicide after the last murder) and Prince Albert Victor, though there is no direct evidence for either.
Was Jack the Ripper ever caught?
No. The killer was never identified or arrested. The case officially remains unsolved.
When did the murders happen?
All five canonical murders occurred between August 31 and November 9, 1888.
What method did the killer use?
The victims’ throats were cut, followed by abdominal mutilations and, in some cases, removal of organs.
Where can I see the original letters?
The original “Dear Boss” and “From Hell” letters are held by The National Archives in London and can be viewed online via their digital catalogue.
Henry William Morgan Harrison is a staff writer for NorwichWire.co.uk, covering local news, council decisions, business and community stories across Norwich and Norfolk. He works under Editor-in-Chief William Hargreaves and Managing Editor Clara Benson, following the newsroom standards for sourcing, verification and fact-checking set out in our editorial policies.