Naming Jack the Ripper: The Biggest Forensic Breakthrough Since 1888 (23 page)

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 of 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:

‘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.

The results of the NMR analysis of the shawl showed the composition of the dye used on it. The molecules were very complex and this suggested that it was a natural dye not a synthetic one (which
would have a much simpler profile). Also, as the dye was soluble in water, it again suggested natural pigment. Natural dyes are the oldest types in use and were invariably derived from sources such
as roots, berries, plants and fungi. The blue dye samples taken from the shawl had similar properties to woad, a very common blue dye derived from the plant
Isatis tinctoria
which has been
used for thousands of years. This was a massive boost, another huge step along the road, and I was beginning to feel that luck was definitely on my side.

While Jari was working in his lab I went on to one of his computers to research the origins of synthetic dye. It was first created, by accident, by William Perkin in 1856 and caught on swiftly,
replacing natural dyes by the 1870s: synthetic colourants cost less, offered a huge range of new colours and they gave better visual qualities to the materials they were used on (I discovered that
William Perkin actually lived in the East End, in Cable Street, and I have since been to look at the blue plaque on his house, grateful that his discovery helped us determine the age of the
shawl).

Natural dyes also required a mordant which would fix the colour and a variety of natural substances were used to do this. The most common were alum, tin, chrome and iron, but sometimes human
urine was used. The mordant improves the fastness of the dyes; however, they were not as water-resistant as synthetic dyes. Because of this, items like shawls were not necessarily washed, and often
just given a good airing or an
application of some fragrant plant such as lavender. As Jari told me, if my shawl had ever been put into a modern washing machine the entire
blue section would have dissipated, and even gentle hand washing would have seen most of it leak out. The fact that it was a natural pigment, not synthetic, also explained why the small stains
which were believed to have been made by semen affected the dye in the way they did, effectively giving the spots a ‘bleached’ look where the semen had made the natural pigment
deteriorate. Natural dyes absorb more: a synthetic dye would have repelled the stains, and they would probably not have survived.