All That Remains: A Renowned Forensic Scientist on Death, Mortality, and Solving Crimes

by Sue Black

What I do not have is a maudlin sentimentality about death and the dead.

One does not, and cannot, exist without the other and, no matter how much modern medicine strives to intervene, death will ultimately prevail.

Forensic pathology seeks evidence of a cause and manner of death – the end of the journey – whereas forensic anthropology reconstructs the life led, the journey itself, across the full span of its duration.

The longest-living person in the world whose age could be verified was Frenchwoman Jeanne Calment, who was 122 years and 164 days of age when she died in 1997. In 1930, the year of my mother’s birth, female life expectancy was sixty-three, so on her death at seventy-seven she exceeded the norm by fourteen years.

If they are to dissect a cadaver for the first time without experiencing crippling empathy, they must, while remaining respectful and ensuring that dignity is preserved, be able to train their minds into viewing the body as a depersonalised shell.

That first incision stays with every student, however blasé they pretend to be.

When the fascination outweighs the drawbacks, anatomy imprints itself on your soul and you will consider yourself for ever a member of a privileged elite: the select few who have seen and been taught the secrets of human construction by those who have chosen to allow you to look inside their own bodies.

Formaldehyde is a disinfectant, a biocide and a tissue fixative and works so well that its aqueous solution, formalin, is still the most commonly used preservative worldwide.

In the 1970s, the anatomist Gunther von Hagens pioneered plastination, whereby water and fat are removed under vacuum and replaced by polymers. These body parts have eternal life. As they will never decompose, we have succeeded in designing a new environmental pollutant.

over 650 muscles must be committed to memory, along with their sites of origin and insertion, their nerve supply and their actions; more than 220 named nerves, their root values and whether they are autonomic, cranial, spinal, sensory or motor; hundreds of named arteries and veins that spread in an arborescent pattern from the heart and back again, their origins, their divisions and the related soft-tissue structures. Then there are the 360-plus joints, and don’t get me going on the three-dimensional relations of the developing gut, tissue embryology, neuroanatomy and its tracts.

What makes us human? One of my favourite definitions is: ‘Humans belong to the group of conscious beings that are carbon-based, solar system-dependent, limited in knowledge, prone to error and mortal.’

The psychology surrounding identity and recognition of ‘self’ is extremely complex. In the 1950s, the developmental psychologist Erik Erikson summarised identity as: ‘Either a) a social category, defined by membership rules and (alleged) characteristic attributes or expected behaviours, or b) socially distinguishing features that a person takes special pride in or views as unchangeable but socially consequential (or a) and b) at once).’

Researchers believe that a sense of identity is a manifestation and extension of the maturation of the concept of self which allows us to develop an intimate and intricate society.

This freedom of individuality, and indeed its suppression, gives humans a unique capability and opportunity to play with their identity and to manipulate, or even change, the perception, portrayal and concept of ‘self’. It is here that I think Erikson omitted the third and most important category of identity, and the one that is most fun to play around with: physical identity.

Forensic science can be used as a toolbox of techniques to reconcile an unidentified body with its previous living identity. Forensic anthropologists look to features of our corporeal biology or chemistry to analyse a trackable and readable history of the life lived, and to confirm whether the evidence recovered matches traces left by that person in the past. In other words, we search for clues of the narrative written in our bodies, innate and acquired, laid down between birth and death.

So, whether we like it or not, it all begins and ends with cells. Death may be a single event for the individual but it is a process for the body’s cells, and to understand how that works, we must be familiar with the life cycle of the building blocks of the organism.

After forty weeks in utero, those two cells will have gone through the most miraculous transformation, becoming a highly organised mass of over 26 billion.

By the time that baby becomes an adult, the cell mass will have expanded to over 50 trillion, grouped into some 250 different cell types forming four basic tissues – epithelial, connective, muscular and nervous – and a variety of sub-tissues. These in turn will combine to construct approximately seventy-eight different organs, divided into thirteen major organ systems and seven regional groupings.

Remarkably, only five organs are considered vital to sustained life: the heart, brain, lungs, kidneys and liver.

Skin cells live for a mere two to three weeks and red blood cells only three or four months.

The four permanent cell types are the neurons in our nervous system, a tiny little area of bone at the base of our skull called the otic capsule, the enamel in our teeth and the lenses in our eyes.

At its most basic level, every cell in our body is comprised of chemicals. Their formation, survival and replication are dependent on a supply of elemental building blocks, an energy source to bind them together and keep them alive and a waste-disposal outlet for their by-products.

So the core components of every single cell, tissue and organ can be obtained only from what we ingest. We are, literally, what we eat.

So we could, in theory, look at the remains of an individual and, from the isotopic signatures in the otic capsule and first molar, discover where in the world their mother was living when she was pregnant with them and the nature of her diet. We could then analyse the remainder of the adult teeth to establish where the deceased person had grown up, and then the rest of their bones to determine where they had lived for the past fifteen years or so. Finally, we could use their hair and nails to locate where they spent the last years or months of their life.

Research using electroencephalograms (EEG) suggests that of all our senses, hearing is the last to go when we are unconscious or dying. This is why palliative care professionals are very cautious about what is said in the vicinity of a patient and why families are encouraged to talk to those who appear comatose.

Given the huge variation in population size over the centuries, we can only guess at how many people in total have expired on our soil but globally, it is believed that over a hundred billion people have lived and died since the appearance of Homo Sapiens about 50,000 years ago – fifteen times as many as the 7 billion or so of us alive in the world today.

In the twenty-first century one in every 39,000 head of population will die every day in the UK – that’s over half a million bodies a year that must be ‘managed’, generally either by burial or cremation.

There are only so many things you can do with dead bodies before they quickly become unpleasant to live with. Five traditional and accepted ways of dealing with them have been used by humankind around the world across the ages. First, they can be left exposed in the open for terrestrial and airborne scavengers to remove, the method still employed in the sky burials of Tibet. Secondly, they can be deposited in rivers or into the sea, where aquatic life will fulfil the same purpose. Thirdly, we may store our dead above ground, via immurement in mausoleums and the like, which has often been the preferred option of the wealthy. The fourth solution is to bury them in the ground, where the invertebrates of the soil will take on the scavenging processes. With the appropriate permission, we can technically bury a body anywhere we like, including on private land, as long as there is no risk of contamination of water sources. Lastly, we can burn them, which is currently seen as the quickest and most hygienic choice, though it does raise concerns about air pollution.

There is more evidence in later centuries of medical cannibalism, arising from a belief among apothecaries in the mystical properties of the corpse. Preparations for ailments such as migraine, consumption and epilepsy, as well as general tonics, were made from various human parts.

Until the Burial Act of 1857, the reuse of graves had been common but as the cemeteries began to fill up, the eviction of some of their tenants rather more swiftly than was felt to be decent often led to public outrage. The legislation made it illegal for a grave to be disturbed, except when official exhumations were ordered. Interestingly, it was only opening a grave that constituted an offence. It was not against the law to actually steal a dead body – as long as it was naked.

In 2007, a shake-up of the Local Authorities Act in London, where the space problem is most acute, paved the way for boroughs to exhume remains and place them in smaller containers before reburying them, as long as the grave is at least seventy-five years old and there are no objections from leaseholders or relatives. This allows them to reclaim graves where there is room for more bodies not necessarily related to the original incumbent. In 2016 the Scottish Parliament enacted similar legislation.

With an estimated 55 million people dying every year worldwide, the problem is of, course, not restricted to the UK. The cities most affected are those that do not have a tradition of grave recycling.

Many cities around the world, especially in Europe, have historically taken a slightly different approach, routinely removing bones from the ground or vaults and transferring them to vast underground catacombs or ossuaries, where the artistic skills of the custodian were given free rein. The largest of these is under the streets of Paris, where nearly 6 million skeletons lie, and perhaps one of the most ornate is the Sedlec ossuary in the Czech Republic, built in 1400 to house the skeletons removed from the church’s overcrowded cemetery.

Germany and Belgium, for instance, provide public graves free of charge for around twenty years. After that, if families do not choose to pay to retain them, the occupants will be moved deeper into the ground or to another site, sometimes a mass grave.

It is common practice in warmer climates, for example in Spain or Portugal, where bodies decompose more rapidly, for remains to be interred in the ground for a shorter period. If families then wish, the bones can be transferred to cemetery wall vaults for as long as payment is made. Ultimately, when there is no close family left, they are evicted.

But burial, of whatever duration and whether in the ground or within monuments, is falling out of favour. The 30 million feet of wood, 1.6 million tons of concrete, 750,000 gallons of embalming fluid and 90,000 tons of steel that are buried underground in the United States alone are a stark illustration of its polluting effects.

Not surprisingly, the highest percentage is found in countries where cremation is the cultural norm or traditional choice for religious reasons, chiefly those with large Hindu or Buddhist populations. Japan tops the world cremation league table with 99.97 per cent, closely followed by Nepal (90 per cent) and India (85 per cent). In numerical terms, China has the most cremations – nearly 4.5 million a year.

Modern society likes to keep pushing the boundaries and newer ‘greener’ options are starting to emerge (cremated ashes are pretty much devoid of major nutrients). One is ‘resomation’, which involves alkaline hydrolysis. The body is placed into a vat with water and lye (caustic soda or sodium hydroxide) and heated to 160°C under high pressure for about three hours. This breaks down the body tissues into a greenish-brown liquid, rich in amino acids, peptides and salts. The remaining brittle bones are reduced to powder (principally calcium hydroxyapatite) by a cremulator and can then be scattered or used as fertiliser.

Another method, ‘promession’, works by freeze-drying the body in liquid nitrogen at -196°C and then vibrating it vigorously to explode it into particles. These are then dried in a chamber and any metal remnants are separated out with a magnet before the powder is interred in the top layers of soil, where bacteria will finish off the process.

Skeletons are more than dusty, dry old relics: they are the footnote to a life lived, sometimes retaining sufficient resonance to ensnare the imagination of the living.

Perhaps there has been no report at all because nobody realised the person was missing, or there was no one who cared sufficiently to raise the alarm. Some may see that as a sad indictment of society but the fact is that some people do not want to interact with others or to be part of a community, and as long as they are doing nothing illegal, their right to privacy and anonymity has to be respected.

Sometimes, in the middle of a big city, surrounded by millions of people, you can simply be hidden in plain view.

However, we are all aware of the restraints imposed by the real world and, given the ever-increasing numbers of people who go missing, there will be those who are never found, dead or alive. Virtually every UK police force holds human remains which, despite their best efforts, remain unidentified (‘unidents’). Every year some of these will be buried without their given names, unbeknownst to their families and friends, because the investigative authorities have been unable to establish who they were in life.

The biggest challenge is posed by a body found unexpectedly in an isolated place, maybe decomposed, and carrying no circumstantial evidence that could lead easily to their identification. There may be no hits, either, on DNA or fingerprint databases.

The genetic norm for the human genome is the presence of forty-six chromosomes in twenty-three pairs. One of each pair – half of your nuclear genetic composition – is donated by your mother and half by your father. Twenty-two of the pairs, while differing slightly from each other, have the same dual ‘form’ (a bit like pairs of vaguely matching black socks) while the twenty-third, the sex chromosomes, carry sex-related genetic information and are therefore quite distinct from each other (like mismatched socks of different colours).

The developing embryo has a genetic sex from the moment the sperm fuses with the egg, but for the first few weeks of its development it appears to be asexual, with no obviously male or female external or internal characteristics. Even by eight weeks after fertilisation, there is little sign in the soft tissue of a human embryo to indicate whether it will become male or female, but by twelve weeks we start to see evidence of which sex the fetus may be. When Mum is having her first ultrasound scan, it might be possible to determine the sex of the fetus from the visible external genitalia.

The centre of ossification (where bone first forms) at the knee will be visible around birth – indeed, its presence on an X-ray was used in the past as an indicator that a baby had reached full term and that the fetus was therefore considered to be clinically viable. This was important in the prosecution of mothers who concealed full-term births, which carried a harsher penalty than concealing the stillbirth of a fetus.

An adult hand, for example, has around twenty-seven bones, whereas in a child of ten these will be made up of at least forty-five separate parts. This makes it a good witness in establishing age in life as well as in death. As it is also easily accessible, and the most ethically acceptable part of the body to expose to the ionising radiation of X-ray, it is often used to determine whether someone presenting themselves as a juvenile for immigration or refugee purposes really is a child.

We can be reasonably accurate to within five years with people up to about forty years old, but after that changes in the human skeleton are largely degenerative and, to be honest, we all fall apart at different rates, depending on our genes, our lifestyle and our health.

The average height for a female is 5ft 5ins (1.65m) and for a male 5ft 10ins (1.78m). Of course, stature is strongly influenced by genetics and environment. If