Jack the Ripper's identity discovered?

In the late 1800s, a killer stalked the streets of London.  He was dubbed 'Jack the Ripper' but his real identity has been a source of speculation ever since.

Now, an author and a scientist working together have used genetic techniques to apparently confirm his identity.  Their work builds on suspicions that the ripper might have been a Jewish immigrant called Aaron Kosminski who had fled persecution in Poland with his family to Mile End in London in 1881.  But no one would testify against him and to date, no one has ever been condemned or convicted for the gruesome murders of at least 5 East End women.

But writer and Ripper enthusiast Russell Edwards tracked down at an auction in Suffolk, a blood-stained shawl that were said to have belonged to one of the victims - a woman called Catherine Eddowes.  Russell then hunted down Liverpool-based John Moores University scientist Jari Louhelainen who specialises in recovering DNA from old artefacts.  He was able to extract one of the forms of human DNA present in our cells called mitochondrial DNA from stains on the shawl which included blood from the victim and semen stains left by the ripper.  And he then matched those DNA profiles to living descendants of both parties.  Strongly suggesting that Aaron Kosminski was the ripper.  Chris Smith spoke to Jari Louhelainen to hear how he did it.

Jari -   The DNA testing started slowly because we have to avoid surface contamination.  So, material which was on the surface like someone touching the shawl and all kinds of debris like even dandruff and so on.  So, it took some time, but in the end, we managed to extract a DNA sample of these stains.  So, in any object or surface, DNA falls apart with age.  So, in order to see the big picture, we need to put these bits back together like a jigsaw puzzle.  That enables us to read the complete sequence.  After this, we could then compare this to the descendant's DNA and verify that the object belonged to one of the murder victims.  In the beginning, we didn't have the descendants so we had to track this person down and we thought it would be nearly impossible.  But Russell had seen her in a BBC programme by accident.  I think it was Find My Past.

Chris -   So, you get DNA from this surviving descendant of this person who was killed by Jack the Ripper allegedly and you get her DNA profile and then compare it to what comes off the shawl.

Jari -   Yeah, that's it.

Chris -   And what do you find?

Jari -   It was a perfect match as long as we could see.  So, this is mitochondrial DNA.  Similar to this is for example, Richard III case where they used in the same way mitochondrial DNA.  So, that gave us enough confidence that we could continue this where it's beginning to look like that indeed it belonged to the murder victim.

Chris -   Indeed, it proves that this shawl must've been in contact both with the victim but also potentially, in contact with the person who did the crime.

Jari -   Yeah and that was the hard part.  I thought we are done here until I found some stains which looked like a sperm or semen stain.  I couldn't understand why these are here as well and I told this to Russell and his eyes lit up and he said this is exactly what has been reported about Jack.  This is his way of operating and this is a great find.

Chris -   So, what you're saying is there was a sexual element to the crimes he committed and that this was some evidence of that left behind.

Jari -   Exactly.  Now, at this point of course, we don't have any material from these stains.  So, we started hunting that and I'm not an expert on that so I asked my friend at the University of Leeds, Dr. David Miller to have a look.  He didn't find the sperm heads but found the epithelial cells which are associated with the sperm head.  Just a very few of them and they were in bad condition.

Chris -   Did that yield DNA nonetheless despite the poor condition?  Did you get DNA from that semen stain?

Jari -   Yeah.

Chris -   So now, you're in a position where you've got a shawl which has the genetic markings associated with the person who was a known victim of Jack the Ripper.  You also now have bodily fluid remnants which are consistent with this guy's modus operandi, how he was alleged to have killed his victims, and you can get DNA from it.  So, that still leaves an unfinished part of the puzzle which is that you've just got a DNA profile from a stain.  How do you know that this stain comes from the ripper himself?

Jari -   Well again, this was one of these things that we have to find the descendant.  I thought that even if we find this person, it would be impossible to sort of get a permission to use her DNA.  Russell then tracked this person down with the help of genealogists and he managed to get this person to cooperate.  So, what we used was mitochondrial DNA and we also got the genomic DNA from the cells which were associated with the sperm heads and managed to get the hair and eye colour.

Chris -   In other words, you get a genetic match with the surviving descendant of Jack the Ripper.  How much certainty do you have that this is what you think it is?

Jari -   So, this work is based on mitochondrial DNA in both matching the victim and matching the suspect.  So, this is not valid in modern court, so there's some bit of uncertainty in that sense about the same level as with the Richard III case where they use also mitochondrial DNA.  What we have is strongly suggesting that this is the case and I think Russell is using my DNA work and his own sort of circumstantial evidence to say very firmly that this is 100% conclusively Aaron Kosminski.  But my DNA work actually just gives a strong suggestion at this point and it needs to be verified.

Chris -   John Moores University scientist Jari Louhelainen who worked with author Russell Edwards on naming Jack the Ripper which is also the title they've chosen in publishing their book to tell the story.