Aaron Kosminski As Prime Suspect

Recently I began work on what I though would be an easy YouTube video to produce – a video about Aaron Kosminski.

Just by way of a brief recap – Aaron Kosminski is reputed to have been the favoured suspect of the two highest ranking police officers with direct involvement in the Jack the Ripper and Whitechapel murders.

Those two officers were Assistant Commissioner and head of the Criminal Investigation Department Robert Anderson and Chief Inspector Donald Sutherland Swanson, the man tasked with reading and assessing every but of evidence that was coming in from the investigation into the crimes.


You will read over and over again that they both considered and named Aaron Kosminski to be their prime suspect, and, so it is reasoned, given the fact they were in a position to know all the evidence against all the suspects, then, if he was their favoured suspect, then he must be the leading contender for the mantle of having been Jack the Ripper.

So, as I began work on the video, I thought it would be a relatively easy one to put together and publish. You can watch the finished video below.


The problem is that nothing is ever simple and straightforward when it comes to the Jack the Ripper case – and that holds true many times over as far as the suspects are concerned.

And, as I began work on the video, it soon became more than apparent that, contrary to what has been said and written over the years, neither Robert Anderson nor Chief Inspector Swanson had actually named Aaron Kosminski as their prime suspect.

Robert Anderson, didn’t even name his prime suspect, but, instead, simply stated in his autobiography, The Lighter Side of My Official Life, that:-

“…”undiscovered murders” are rare in London, and the “Jack-the-Ripper” crimes are not within that category…In saying that he was a Polish Jew I am merely stating a definitely ascertained fact.”

A portrait of Sir Robert Anderson.
Sir Robert Anderson (1841 – 1918). Copyright, The British Library Board.


So Robert Anderson didn’t actually name his prime suspect, as is is often claimed, but merely stated that he “was a Polish Jew”, adding elsewhere that:- “he was living in the immediate vicinity of the scenes of the murders.”


The main fact put forward to back up Aaron Kosminski’s candidature for the mantle of having been Jack the Ripper is that Chief Inspector Swanson did actually name him in annotated margin notes that he added to his copy of Anderson’s memoirs.

But, yet again, this is simply not true.

What Swanson actually wrote, in what is now known as “the Swanson marginalia”, was that:-

“In a very short time the suspect with his hands tied behind his back, he went to Stepney Workhouse and then to Colney Hatch and died shortly afterwards – Kosminski was the suspect.”

So, Swanson didn’t actually say that the suspect was Aaron Kosminski, he simply stated that somebody called Kosminski was their suspect and was the man about who Robert Anderson had written.

An image of Chief Inspector Swanson.
Donald Sutherland Swanson


It wasn’t until the 1980s that author Martin Fido combed the Colney Hatch records and found that the only Kosminski who went to the asylum around that time was Aaron Kosminski – and from then on his name became linked with Swanson’s Kosminski in the minds of many ripperologists.

The major problem is that, Aaron didn’t – as Swanson wrote was the case with his Kosminski – die in the asylum shortly after being sent there. In fact, in 1894 he was transferred to Leavesden Asylum where he remained for the rest of his life, before dying their in March, 1919.

And, it must be said, that even Martin Fido noticed the discrepancy and was not convinced that Aaron Kosminski was Swanson’s Kosminski.


So, that was the problem that confronted me as I began presenting my case against Aaron Kosminski.

In the end, I opted to not confirm that he was Jack the Ripper, as I truly believe that there is insufficient evidence to say that this was the case.

Rather, I opted to present the evidence and then leave it to viewers to draw their own conclusions.

After all, there is one mantra that I spout over and over again on my tour of the murder sites, and that is, when it comes to Jack the Ripper, the only certainty is that nothing is certain.