Before long, two sealed samples of Karen’s DNA, taken from her mouth, were sitting in my freezer to protect them from any contamination or degradation, ready to be worked on. I delivered them to Jari, and was only happy when I knew they were safe in his freezer. I knew that if Karen’s DNA matched that of Catherine Eddowes, we could prove, once and for all, that this old piece of stained clothing was the only genuine, verifiable artefact in the Ripper case that could really lead somewhere. But progress on this strand of the investigation would have to wait until Jari had time.
In the meantime Jari turned his attention to acquiring evidence from the stains that had fluoresced green and which suggested the presence of semen, although as ever Jari was cautious and pointed out that there were other possibilities. The worst case scenario was that the stain was washing powder, but we were both convinced by this stage that the shawl had never been washed.
Talking about luck: that has got to be one of the greatest strokes I, and anyone else interested in solving the Ripper case, could possibly have had. After all the hands it has passed through, and after the story that the original owner, Jane Simpson, hated it because of the bloodstains, it is nothing short of remarkable that nobody, in the shawl’s long history, has ever tried to clean it up by washing it. If they had, all the vital evidence would have been lost.
I knew that the presence of male bodily fluids on an item that could be linked to a murder meant a strong likelihood that the killer’s DNA was on it. There are murder cases, particularly serial killer cases, where the murderer obtains sexual gratification from the act of killing or mutilation and promptly ejaculates, either on the body of the victim or on clothing belonging to them. One that I had known about for some time was the case of Peter Kürten, the ‘Düsseldorf Vampire’, who killed men, women and children in a series of sexually motivated murders in 1929. Kürten obtained sexual gratification from his crimes and the amount of times he stabbed his victims often depended on how long it took him to achieve orgasm. The sight of blood was an integral part of his pleasure and a famous story about Kürten is that he wished to hear his own blood gushing into a bag immediately following his beheading. Dennis Rader (the ‘BTK Killer’ – Bind, Torture, Kill), Andrei Chikatilo (the ‘Rostov Ripper’) and Peter Sutcliffe (the Yorkshire Ripper’) are other notorious serial killers whose horrific acts culminated in ejaculation. Semen and the DNA contained within it has been used to secure criminal convictions and also, in other cases, to exonerate the accused. A good example of this is one of the earliest uses of forensic DNA comparison in Britain in the 1980s, in a case that became known as the Enderby murders.
In November 1983, a fifteen-year-old schoolgirl, Lynda Mann, was found dead on a river towpath in Narborough, Leicestershire, having been strangled and raped. The only clue was a semen sample taken from Mann’s body from which forensics deduced that the owner’s (and most likely the killer’s) blood group was Type A, but in the absence of any other evidence, the case went unresolved. Almost three years later, another young girl, Dawn Ashworth, was found raped and murdered on another footpath in Enderby, only a mile from where Lynda Mann had died. Again there were traces of semen which was analysed and which showed the same blood group as that found on the previous victim. This made it highly likely that it was the same man who raped and murdered the two girls.
Following extensive investigations, a man named Richard Buckland was arrested and confessed to the second murder, but strongly denied any involvement in the first. Investigators decided to try a new and untested technique: ‘genetic fingerprinting’ through DNA analysis. Such testing had already been used in paternity suits to determine the real identity of a child’s father, but it had never before been used in a criminal case. It was felt that this ‘genetic fingerprinting’, would solve the case, as well as confirm the technique’s viability, so a sample of Buckland’s blood was taken for analysis. To everyone’s surprise, there was no match between his DNA and those taken from the semen found on the bodies of the two girls, and Buckland became the first person in criminal history to be proven innocent based on a DNA test.
With the search to find the killer now back on, all the men from the area around where the bodies were found who had Type A blood were asked to voluntarily submit to a DNA test. Over 5,000 men agreed to do it, but the object was actually to find any man who would not willingly take the test because they had something to hide. Colin Pitchfork, who had previous convictions for indecent exposure and who was already of interest to the police, wanted to avoid detection and so persuaded a friend to take the test in his place, providing him with false identification and a cash payment of £200 for his troubles. Unfortunately, when the friend foolishly bragged in a public place about what he had done, he was overheard by a woman who immediately contacted the police. With attention now on Colin Pitchfork, he confessed and his genetic fingerprint turned out to be identical to that found in the semen at the crime scenes. In September 1987 he became the first person to be convicted of murder based on ‘genetic fingerprinting’.
Since then the use of DNA in forensics has become a standard detection tool, and the science has improved exponentially. Naturally, it was the way forward for us to connect the shawl with both victim and murderer.
In autumn 2012 I took the shawl back to Jari. It was my children’s half-term holiday from school and we were staying with Sally’s family in North Wales. I drove to Liverpool with the shawl and left it with Jari, going back to join my children at the swimming pool in Prestatyn. Later in the day I went back to Jari’s lab, taking my father-in-law with me, to collect it again. There was nothing Jari could tell me there and then, other than that he had taken the samples he needed.
He had used the same extraction method he’d used to take the blood samples from the shawl. Material from the possible semen stains was extracted from the relevant locations and placed into three separate vials. As routine procedure, they were put into a special freezer at minus 80°C for maximum preservation. The likelihood of sperm surviving this long was extremely slim and the standardized forensic methods for sperm detection tend not to work with samples as old as the ones we had. When ejaculated sperm ages, the tails are lost first, so the hypothesis Jari explained to me was that if the sperm had dried quickly, and the cells were trapped within the textile, we might be lucky and find at least a few sperm heads which had avoided natural degradation.
Once again, we had a stroke of luck. Jari had been to dinner with a colleague and old friend from Leeds University, David Miller. David is the Reader in Molecular Andrology at the Reproduction and Early Development Group at the University of Leeds Institute of Genetics, Health and Therapeutics. Quite a mouthful, but the importance to us is that David is, in Jari’s words, ‘a world class expert in sperm head analysis’, one of very few in Britain. He is a specialist in fertility and the causes of infertility. They met when Jari and his wife rented David’s huge Victorian mansion in Leeds in 2001. David contacted Riitta when he heard they were looking for somewhere to live, as David was going to Detroit to work, and he wanted tenants he could trust: he chose Jari and Riitta in preference to some burly Australian sportsmen. The house was newly renovated and although Jari was initially put off by its age, the minute he saw it he said Where do I sign?’
By coincidence, at that time Jari was doing DNA microarrays (don’t ask me!) for Cancer Research in Leeds, and David was invited to do similar work in Detroit. The two families are now close friends.
‘Over dinner we talked science, of course. That’s what scientists do,’ Jari said.
‘I asked him if he thought sperm heads could survive for so long, and he told me it was possible, as sperm heads are very stable.’
What’s more, David was willing to work on our samples. When they had coordinated dates, Jari took the three vials home with him to Bradford, and temporarily stored them in his home freezer before Riitta delivered them personally to David as she was working on the same campus.
It was on the 12th day o
f the 12th month of 2012, as I was driving into London, that my car phone lit up with the information there was an incoming call from Jari. I pulled over, because I know from experience that I need to concentrate when talking to Jari. I can’t take in scientific details while I’m negotiating London traffic.
We’ve got some cells,’ he said.
It was a massive moment, and I was speechless.
Jari went on: ‘They are not sperm heads, they are squamous cells, from the epithelium.’
Somewhere in the dark recesses of my memory I knew I had heard the word ‘epithelium’ when I was doing A level Biology, but if I ever knew what it was, I had certainly forgotten by now.
What does it mean?’
Jari explained as simply as he could to me.
The epithelium is one of four basic types of tissue which is present in the human body, either outside or inside. The epithelium is widespread in living organisms – in humans it coats or lines numerous organs and can be found on the insides of the lungs, the gastrointestinal tract and the reproductive and urinary tracts, among other places. Jari told me there was a strong possibility that these cells had come from the urethra during ejaculation, because they originated in a stain that fluoresced like semen under his lights.
The most important piece of information he gave me was, We can probably get DNA from these samples.’
I sat in my car at the side of the road, stunned. It seemed now we could have access to the DNA not just of the victim, but of the Ripper himself. It was hard to take it in.
Jari told me that David Miller was concerned about the absence of sperm in the sample; however, the evidence of squamous cells meant that it could not be ruled out that some sperm could have been there (which could be revealed in some future analysis). For the moment he felt that finding the epithelial cells meant that no further investigation was necessary.
When I got home I rang David to confirm what Jari had told me, and to thank him for doing the work for us. He talked me through the testing he had done, then followed up by sending me an email, complete with images of three views taken down a light microscope with 400x magnification. He gave me a detailed explanation of the procedure he had followed, and then he wrote:
The fact that I didn’t find any sperm does not automatically exclude their presence, but considering that squamous cells are a minor component of a typical semen sample (they get into the semen by mechanical sloughing from the urethral epithelium during ejaculation), I would have expected to see them if they had been there. On the other hand, squamous cells like these are also found in other bodily fluids including saliva, sweat etc (basically any fluid that washes over or bathes an epithelial surface).
‘Mechanical sloughing’ in this case means that when ejaculation occurs, epithelial cells from around the urethral tract are dragged out with the semen and will be part of the resulting ejaculate. As far as I was concerned at that moment, the most important bit was that the cells could provide us with the crucial DNA. And because the stain fluoresced like semen under Jari’s forensic lights, it was the likeliest candidate as a source.
I immediately emailed David to make absolutely certain I understood the main fact: ‘From what I gather from our conversation, you can get DNA from the cells you have found. Is that correct?’
Two minutes later his reply pinged into my inbox.
Yes, that’s correct.’
I was thrilled. I knew getting the DNA would be difficult. There were twelve cells isolated altogether, and David had placed them on microscope slides ready for any further testing and potential extraction of DNA. There would be an extremely limited amount of DNA and the microscope slide might have contaminants from the shawl which could ruin the whole process, but in principle it could be done. We were on our way with another vital strand of the whole investigation. That portentous date, 12/12/12, had lived up to its promise.
I think the news that we had been successful in Leeds with the sperm head analysis, which had found the epithelial cells, helped Jari understand the importance of the whole project. He says himself, ‘I got hooked at this point.’ He, too, could see that we were on the brink of something very big, and he stepped up a gear. He had always been willing to do my research when he could, alongside his day job: now he was prepared to go above and beyond the call of duty to get on with it.
One thing he wanted to do before embarking on the DNA comparison was to definitively age the shawl. The DNA work would be time-consuming and costly, but in the meantime he could get on with this. From my research I was sure it was a silk shawl from the Russian factory of Pavlovsky Posad, and Diane Thalman had confirmed it was in all probability early nineteenth century. But that didn’t amount to proof, and both Jari and I understand that to make this case watertight, we need scientific proof at all levels, not just expert opinion.
So on 2 January 2013 I drove to Liverpool again with the shawl. The university was still on its Christmas break, but Jari went into his lab specially to do an absorption test. Previously while taking the DNA samples, Jari had noticed that the blue dye of the floral pattern appeared to be highly water soluble, and came off" easily, whereas the brown dye did not come off at all. Where the stains were mixed in with the dye, Jari had to separate the dye out in order to get samples from the stain. The first attempt at the absorption test failed, as the colour just disappeared before Jari could start testing it.
The fact that the blue dye came off so easily told us one piece of information: the shawl could never have been used as an outer garment, because rain would have made the blue dye leak. This underlined that it could not have belonged to Catherine Eddowes: with her itinerant lifestyle it would certainly have been exposed to rain. Just before her death she and her partner John had walked back to London from the hop fields in Kent, and because she had nowhere to live she had all her clothes on when she was murdered: there is no possibility that the shawl would never have been wet if it was hers.
The difference between the two dyes also suggested that the shawl was not machine printed, but that the dye was hand-applied. Now Jari was going to test it to find out the type of dye used, which would help date it.
While Jari was working on it I wandered into the museum next door to his department at the university. It was somewhere to keep warm, as it was a bitterly cold day. The place was full of parents and children: it was still the school holidays. I strolled around, trying to occupy myself looking at the exhibits, while all the time thinking about what was going on in the lab.
Jari carried out an absorption test using a spectrophotometer on the blue area of the shawl. The test shows where the fabric is absorbing light, which differs between dyes. For example, 6,6’-dibromoindigotin is considered to be one of the oldest (if not the oldest) pigments. It is a major component of Royal Purple or Tyrian Purple, which is known to have been very expensive. This was one possibility for the blue dye. Another candidate was indigo. With just one microlitre of the dye extract (one twentieth of a small droplet of rain, barely visible to the human eye), Jari could see that the dye spectra closely resembled the known spectrum of indigo, with a peak of 620 nanometres but not the dibromoindigo (Royal Purple). Looking at the absorbance spectrum did not give a full confirmation of the chemical composition of the dye but it showed that only one compound was applied to the blue section, and therefore we knew that the shawl was definitely not screen printed, which was very encouraging news. Screen printing was introduced in 1910, and if it had been dyed in this way the game would have been over.
When I returned to Jari’s lab he showed me a graph with the blue peak. He told me that the best way to proceed was to look at the fabric with a nuclear magnetic resonance instrument, and for this we would need to enlist the help of a colleague of Jari’s, Fyaz Ismail, who is the Senior Lecturer in Medicinal Chemistry, Drug Design and Discovery Module Leader at LJMU. Fyaz is a lovely, jolly character who we nicknamed The Chemist. So later I took the shawl back up the motorway to Liverpool. I knew that The Chemist would need
an actual sample of the shawl, but the size of the sample took both Jari and me by surprise: the test needs two samples, one of each colour, each about a centimetre square. I was horrified: by now I was so protective of the shawl that it felt like a piece of my own body was being cut off, and Jari said that the expression on my face looked as if I was about to have a heart attack. Nonetheless, it had to be done. Jari shared my surprise if not my horror: he is used to working in a micro/nano scale with everything.
The NMR instrument is huge and would fill an average size living room. It costs around half a million pounds and has very strict safety protocols because it can be deadly. The strong magnetic fields near the instrument can stop not just watches but pacemakers, defibrillators, and can pull out metal surgical implants or prosthetics, and can make hairpins fly at high speed. Anyone wearing a metal necklace can be choked to death.
NMR can help determine the structure of the material being analysed as well as additives used in textile products. It is a research technique that exploits the magnetic properties of certain atomic nuclei and determines the physical and chemical properties of the atoms or molecules in which they are contained, thus providing information about the structure, dynamics, reaction state and chemical environment of molecules. This is achieved by bombarding the samples with radio waves of a fixed frequency. The nuclei contained within the molecules absorb that radio frequency when an external magnetic field is introduced and reaches an appropriate level. When the radio waves and magnetic field are at the right level, the nuclei can absorb those radio waves. Different nuclei absorb radio waves at different rates, dependent on the environment the nuclei are contained in and it is the rates of such absorption which gives us clues as to what the molecules are. The results appear as a form of graph with peaks and troughs, and from this graph we can determine the nature of the molecules under study. In other words, NMR can tell us what something is made of.
Naming Jack the Ripper: The Biggest Forensic Breakthrough Since 1888 Page 17