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

by Sue Black

Indeed, after my own grandmother died in 1976 and we opened the grave for her to be buried with her husband, we found a child’s coffin in our lair.

Anyone who thinks forensic anthropology is sexy should spend a day in Old Monkland Cemetery in January, chilled to the bone, up to their knees in mud and clay with the excavation walls continually in danger of collapsing around them and creating their own tomb.

Without a body, investigating what has happened to the missing can be extremely difficult. It can be just as problematic when a body is found and there are no obvious clues as to the person’s identity.

A report may have been made in a different country, to a police force distant from where the body was found, or may have been recorded many years before, archived and forgotten. 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.

We were once called to a council flat in London occupied by a Chinese gentleman. He had not paid his rent in over eighteen months and eventually the council entered the property to repossess it. They were shocked to find the tenant in bed, wrapped tightly in his duvet like a cocoon. He had died in his sleep over a year before and was almost totally skeletonised. The bedding and mattress had acted like a wick, drawing away all the moisture produced by decomposition, leaving the remaining soft tissue desiccated and effectively mummifying him.

His identity was accepted by the coroner on the basis of his ancestry and age. Sometimes, in the middle of a big city, surrounded by millions of people, you can simply be hidden in plain view.

In an ideal world, our police forces would have unrestricted budgets and unlimited personnel to devote to searching for missing persons and matching them with unidentified bodies. 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.

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. This is when forensic anthropology comes into its own and offers the best and sometimes the only chance of reuniting the deceased with their identity in life.

Humans fall into several different general descriptor categories that can help to narrow the range of possibilities. The more recent the death, the more likely we are to be able to accurately determine the four basic components of biological identity: sex, age, stature and ancestry.

The determinant of the first component of our identity, sex, should be very straightforward as we expect it to be bimodal – male or female. The term ‘sex’ is used very specifically in our field and is not to be confused with ‘gender’: the former is used to denote the genetic construction of the individual while the latter relates to personal, social and cultural choices and may be at odds with our biological sex.

These days, some hospitals choose not to confirm the sex of a baby, ostensibly because of staff shortages and the time required to make the assessment, but they will have other concerns, such as the risk of litigation if they get it wrong and the prevention of selective abortion by couples whose culture values one sex above the other.

what he or she will be looking for on the image is the same visual external evidence used by the nurse, midwife or whoever is present to announce a baby’s sex when it is born – if it has a penis, it is a boy, if it hasn’t, it is a girl – which then becomes its legal description. There is much wrong with that as a basis for determining the legal sex of a child, biologically, socially and culturally.

From that moment on, the agenda for a baby’s entire childhood is usually set in stone. They will be brought up as either a boy or a girl, with all the cultural trappings that definition brings, purely on the basis of whether or not they have a visible penis.

In the vast majority of cases the designation of sex when we are born is correct but the forensic anthropologist must leave room for other possibilities.

If you are in any doubt, ladies, wait until after menopause, when oestrogen declines, allowing testosterone to assert itself, and watch your beard and moustache grow. The bearded lady beloved of Victorian circuses was not a freak of nature but a perfectly normal human variant.

Sex, or what we perceive to be maleness or femaleness, is largely about the interaction between genetics and biochemistry and the effects this has on all of the tissues of the body, including the brain. Imagine a genetically pink embryo that goes into overproduction of testosterone (as happens when a gene mutation causes adrenal hyperplasia), or a genetically blue embryo that either does not switch on its SRY gene or fails to produce enough testosterone (adrenal hypoplasia), or goes into overproduction of oestrogen, and you start to see how the interplay between genetic sex and physical appearance or psychological identity become conflated.

Assigning biological sex becomes trickier as a body starts to decompose. External genitalia deteriorate quite rapidly after death and examination of internal anatomy through postmortem dissection may be of limited assistance.

Cephalopelvic disproportion is seen less often nowadays, mainly as a result of improved health but also perhaps as a rather brutal example of the survival of the fittest, whereby feto-maternal mortality has resulted in the phasing out of unsuccessful pelvic shapes.

The World Health Organisation (WHO) reports an estimated 340,000 maternal deaths, 2.7 million stillbirths and 3.1 million neonatal deaths every year, almost all in impoverished countries.

Ironically, it seems that determining sex from the pelvic bones may well be achieved with greater accuracy and reliability in archaeological specimens than in recent forensic samples, because the level of sexual dimorphism required to maintain successful childbearing heritage is being lost.

The bone-muscle equation is a simple one: stronger bones are required to withstand the forces exerted by the attachments of stronger muscles. In areas such as the skull, the long bones and the shoulder and pelvic girdles, we see more well-developed sites of muscle insertion.

As the relevant changes we look for in the skeleton do not occur until puberty, sex cannot be determined with any degree of reliability from a child’s skeleton.

If the entire adult skeleton is available for analysis, the forensic anthropologist will probably be able to correctly assign biological sex in about 95 per cent of cases, although different ancestral groups will show variations that we must take into account.

the Dutch are officially the tallest ‘race’ in the world but their babies are not any bigger than those of other Western populations. Not surprisingly, therefore, they have a very low level of obstetric complication because the proportionately larger Dutch female pelvis has not needed to adapt to ensure the safe passage of the baby. Women from other groups who are smaller in stature but deliver babies of the same size are believed to exhibit greater levels of sexual dimorphism in the pelvis as nature has sought to find a shape that will safely accommodate chi...

The shape of the greater sciatic notch in the pelvis, the prominence of the nuchal muscle markings at the back of the neck, the size of the mastoid process behind the ear and the presence of supra-orbital ridging under the eyebrows all hold important clues.

we must always remember that the features on which we are basing our analysis are indicators of the extent and timing of biochemical influences, not proof in themselves of the biological or genetic sex of the individual.

Whereas we are quite successful at establishing the correct biological or genetic sex for an adult but pretty rubbish at it with children, when it comes to the second biological component of identity – age – it is the other way round.

In the early years of life there is a strong relationship between age, facial appearance and size. The face is a reliable indicator of age because of the way it needs to grow to accommodate dental development.

The correlation between age and size in young children is reflected in the way we buy their clothes. These are sold by age rather than measurement because manufacturers can predict with some confidence that, say, between birth and six months, a baby will have a head-to-toe height of about 67cms (2ft 2ins). We don’t look for a dress for a 3ft 5ins child, but for a four-year-old.

when we are examining the remains of a fetus or baby, the length of the long bones within the upper limb (humerus, radius and ulna), and the lower limb (femur, tibia and fibula) will allow us to calculate its age to within a few weeks. With a young child we will be accurate to within a few months, and in an older child to within a range of two or three years.

In children, some bones are comprised of several parts, to allow for growth, which will eventually fuse on maturity. As the pattern of growth and fusion is closely related to age, the stage these bones have reached is a reliable guide. The adult human femur (thigh bone), for example, is a single bone but in children it consists of four different components: shaft, distal articular end (at the knee), a proximal articular head (at the hip) and the greater trochanter on the side of the bone where the muscles attach.

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.

Over half of the world’s population is born without a birth certificate

Once an individual is beyond childhood and adolescence, there is a weaker correlation between age-related features and actual chronological age. 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.

Unfortunately, the one we are really good at, stature estimation, is probably the least important of all four of the biological characteristics.

The anthropologist who asserts absolute confidence in the sex, age, stature and ancestry of a skeleton is a dangerous and inexperienced scientist who doesn’t understand human variability.

We can predict the adult height of a child either by doubling their stature at the age of two (isn’t it incredible that we grow to half our full adult height within our first two years?) or by calculating what is called MPH (mid-parental height). For a boy, in centimetres, the equation is: father’s height + mother’s height + 13 ÷ 2; for a girl: father’s height – 13 + mother’s height ÷ 2.

more commonplace factors such as nutrition, altitude, disease burden, growth variations, alcohol, nicotine, birth weight and hormones will all affect how tall we will be as an adult. With fully favourable conditions, a child will reach their height potential. If they experience adverse conditions in their first fifteen years or so, they are likely to be shorter than expected.

Our height is made up of the length and thickness of all of the components of our body, from the skin on the soles of our feet to the skin on the top of our heads, encompassing bone heights and lengths (calcaneus, talus, tibia, femur, pelvis, sacrum, twenty-four vertebrae and skull), plus joint spaces between these bones and also the thickness of the cartilage between the bones of each joint. With age, cartilage thins and some of the joint spaces collapse. Clinical conditions such as arthritis and osteoporosis will also alter the bones and joints and reduce overall height. And believe it or not, our height varies according to the time of day: we are on average half an inch shorter by the time we go to bed than we were when we got up. We lose most of that height within three hours of rising, as our cartilages settle and compress and decrease our joint spaces.

When a body is found with all the bones pretty much where they should be, there will be a lot of soft tissue still present, so we will get out our tape measure and record the recumbent stature there and then.

We measure the length of each of the twelve long bones (the femora, tibiae, fibulae, humeri, radii and ulnae, of which we have two apiece) on a device called an osteometric board and place the values into appropriate statistical regression formulae for the sex and ancestry of the individual.

I have known of families who have latched on to the vain hope that remains we have examined are not those of their son, even questioning a DNA result confirming his identity, purely because they have been given a most likely height of around 5ft 6ins and he was actually 5ft 7½ins. That is why we provide the full margin of error and suggest a range.

Assignation of ancestry is potentially of enormous interest to the investigative process but often forensic anthropologists are not talking the same language as the police. What the police will want to know is whether they should speak to members of, say, a Polish or a Chinese community. Unfortunately, we are unable to distinguish between groups such as these and others of close biological proximity just from looking at skeletal remains.

While we may quite easily categorise the origins of our ancestors, things have become trickier in the more recent past and I suspect many of us would get a few surprises regarding our own histories if we investigated our genes.

in our smaller, modern world, where interactions have been more common and more frequent over the generations, the genetic signal for each of the four discrete classifications is becoming ever fainter.

What genetics cannot tell us with any reliability is the difference between a man from China and a man from Korea, or a British woman and one from Germany. Therefore it is of no value whatsoever in assisting us with assessing the ancestry of a person descended, for example, from an Indian maternal grandfather, English maternal grandmother, Nigerian paternal grandfather and Japanese paternal grandmother.

We do have computer-based systems that can process a variety of skull measurements and give us suggestions as to the most likely ancestry for an individual, but these must be viewed with some caution. What we will be hoping in such circumstances is that hair or other soft tissue survives that can assist us, or that clues may be provided by personal effects such as clothing, documents or religious jewellery.

Once the four biological parameters have been determined, our next job is to find individual identifiers that will enable us to focus on a single person to the virtual exclusion of all others, using one or all of the INTERPOL-approved primary methods: DNA comparison, dental records or fingerprints.

When we have a potential identity for our body, DNA extracted from the bone can be compared with a sample from a mother, father, sister, brother or children. It may even be possible to acquire the missing person’s own source DNA, perhaps from a toothbrush, hairbrush or ponytail bobble that still holds some shed hair with cells at the base.

The UK National Criminal Intelligence DNA Database (NDNAD), set up in 1995, is the largest national DNA database in the world. Over 6 million profiles are stored there, representing nearly 10 per cent of the country’s population.