How Forensic Anthropologists Read the Skeletons of the Dead For Clues

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The forensic anthropologist’s job is to try to read the bones of our skeleton as if they were a record, moving a professional stylus across them in search of the short, recognizable segments of body-based memory that form part of the song of a life, coaxing out fragments of the tune laid down there long ago. Usually this will be a life that has ended. We are interested in how it was lived and the person who lived it. We want to find the experiences recorded in the bones that will help to tell its story, and perhaps give the body back its name.

Within our discipline of forensic anthropology—the study of the human, or the remains of the human, for medico-legal purposes— there are four basic issues practitioners must address when confronted with a body, or parts of a body. Most of the time they will all be answered when the right person asks the right questions in the right way.

First of all, are the remains human?

When bones are found in unexpected circumstances, there is no point in the police setting up an investigation until this first question has been answered. Advising the police on the assumption that bones are human if they then turn out to belong to a dog, cat, pig or tortoise would be a very expensive mistake. The forensic anthropologist must be certain of the origin of the material in front of them, which means they must have knowledge and experience of the range of bones from common species likely to be encountered in the country where they are working.

As the UK is surrounded by sea, it is very common for the remains of all manner of creatures to be washed ashore on our coastline. Often these are of marine origin, so we have to know what all the different parts of a seal, a dolphin or a whale look like, alive or dead and decomposing.

We need to be familiar with the various characteristics of all of the bones found in agricultural animals such as horses, cows, pigs and sheep; in domestic pets, like dogs and cats, and wildlife—rabbits, deer, foxes and so on. While every bone in every animal is subtly different, there is a commonality to the form because it relates to function. A femur, or thigh bone, looks like a thigh bone, whether it is from a horse or a rabbit: there is just a big size difference and a bit of a variation in shape.

Between species which share a common ancestry, it can be more difficult to distinguish between their bones, for example, to tell whether a vertebra is from a sheep or a deer. There are few animal bones that should be confused with those of the human, provided the investigator has a basic knowledge of anatomy, but there are some to which even forensic anthropologists need to be alert. Human and pig ribs are very similar. The tail bones of a horse can look like human finger bones. The ones most likely to confuse us are those of species with which we share an ancestral link: other primates. This is not a problem that tends to arise very often in the UK, but one of the golden rules of forensic science is never to assume anything, and such cases are not unheard of, as we shall see.

Skeletal remains may be found on the surface of the land or underground. When bodies have been buried we need to take into account that this has been a deliberate act, and that it has usually been performed by a human. We expect humans to bury humans, but they also bury animals that are important to them, primarily pets. While people tend to bury pets where they like, often in their own gardens or woodland, we expect them to bury other people in the proper place—in a cemetery. So when we find a human above ground or buried somewhere unexpected, perhaps in a back garden or a field, there is a long set of questions to be answered about why this might be so. In short, there is an investigation to be had.

Secondly, we need to establish whether the remains are of forensic relevance.

A recently discovered body is not necessarily going to have been recently deposited, and setting up a murder investigation based on Roman remains is not likely to result in a solved case. On TV crime dramas the first question asked of a doctor, pathologist or anthropologist is always, “How long has he been dead, Doc?” This is not always easy to answer but, very crudely, if the body still has bits of flesh attached, if it is still wet with fat and if it smells bad, then it is likely to be of recent(ish) origin and so worthy of forensic investigation.

The difficulty arises when the bones are dry and all soft tissue has been lost. In different parts of the world, this stage will be reached at different times. In warmer climates, where insect activity can be voracious, a body can be reduced to a skeleton in a matter of a couple of weeks if left unburied. If it is buried, the rate of decomposition will be slower because the soil is cooler and insect activity restricted, and skeletonization may take anywhere between two weeks and ten years or more, depending on the conditions. In very cold, dry climates, the body may never completely skeletonize at all. This extensive range of possibilities does not impress the police, but the determination of the time death interval (TDI) is far from being an exact science.

Nevertheless, it is important to establish a reasonable cutoff point beyond which human remains are generally no longer considered to be of forensic interest. Of course, there will be some instances where, regardless of the passage of time, if bones come to light they may remain forensically relevant. For example, any juvenile bones found on Saddleworth Moor in the north-west of England will always be investigated as a possible link to the moors murders of the 1960s, committed by Ian Brady and Myra Hindley. Not all of the bodies of their victims have been discovered and both murderers have now taken whatever further information they might have been able to give us to their own graves.

In normal circumstances, though, if a skeleton belongs to someone who has died more than seventy years ago, it is unlikely that any investigation would establish the circumstances of the death, still less lead to any conviction, and so technically the remains may be considered archaeological. But this is a purely artificial demarcation, arrived at on the basis of the expectation of accountability in relation to a human life span. There are no scientific methodologies that can enable us to be sufficiently specific in terms of determining a TDI.

Sometimes context can help. A skeleton found buried next to a Roman coin in a known archaeological hotspot is unlikely to be of interest to the police. Neither is a skeleton uncovered by stormy weather from the sand dunes in Orkney. But they all have to be investigated, just in case. A forensic anthropologist will make an early assessment and if that is not conclusive, we may send samples away for testing. Measuring the level of C14, a radioactive isotope of carbon, which is created naturally in the atmosphere, in organic matter such as wood or bones is a method that has been used by archaeologists to date their important finds since the 1940s. The level of C14 begins to decrease once a plant or animal dies so, basically, the older the bone is, the less C14 will be present. As this particular radioactive isotope takes several thousand years to disintegrate completely, radiocarbon dating will only help us when remains are five hundred years old or more at the point when they are analysed and won’t get us closer to modern times.

However, in the last century the human race has been the agent of disturbances in our radiocarbon levels through above-ground nuclear testing, and these have introduced manmade isotopes such as strontium-90, which has a half-life of only about thirty years. As strontium-90 did not exist before nuclear testing, if it is detected within the matrix of bones, it can only have got there during the life of the individual. So this can narrow down the date of death to within the last sixty years or so. However, self-evidently, with the passage of time, this methodology will cease to become effective. Never trust the pathologist on a TV show who says that the skeleton has been in the ground for eleven years. Utter twaddle.

Our third fundamental question is: who was this person?

If the remains have been confirmed as human and of recent origin, we need to find out who the individual was when they were alive. Our actual name is not, of course, written into our bones but they can often provide enough clues to lead to a possible identity. Once we have that, we can start to compare them with antemortem data, medical and dental records and familial biology. It is in identification that the critical scientific expertise of the forensic anthropologist is most frequently brought to bear. It is our job to extract the information held by the bones. Was this person male or female? How old were they when they died? What was their ethnic or ancestral origin? How tall were they?

The responses to these questions provide us with the four basic parameters by which every human can be categorized: sex, age, ethnicity and height. They make up a biological profile of the individual: for example, male, aged between twenty and thirty years, white, between 6 ft and 6 ft 3 ins in height. This profile automatically excludes those people reported missing who do not fit, thereby reducing the possibilities. To give an idea of scale, in a recent case, the biological profile cited above resulted in over 1,500 possible names for the police to investigate.

We ask the bones all sorts of other questions in the hope that they might answer. Did she have children? How did her arthritis affect how she walked? Where was that hip replacement done? When and how did she break that radius? Was she left- or right-handed? What size shoes did she wear? There is barely a single region of the body that cannot tell a part of our story, and the longer we live, the richer the narrative.

DNA identification has of course been a game-changer in reuniting the dead with their names. But it can only help if investigators have a source with which the DNA of the deceased can be compared. Source DNA matching requires the individual to have previously given a DNA sample that remains on record. Unless they are one of the minority who do so for occupational reasons, such as police officers, soldiers and forensic scientists, this will only have happened if they have been charged and found guilty of an offence. If the police believe they know who the person was, they can search for source DNA in their house, office or car and have it compared with that of a parent, sibling or offspring. Sometimes a relative may already be on the criminal database and a link can be made via that circuitous route. When molecular forensic science is unable to assist, forensic anthropology, and its focus on the bones, is often a last resource upon which to call. Until we have a name for the deceased, it is extremely difficult for the authorities to establish whether a crime has taken place that needs to be investigated, let alone to conclude the person’s story to the satisfaction of the criminal justice system and their bereaved family.

Lastly, can we assist with the cause and manner of death?

Forensic anthropologists are scientists and, in the UK, are not generally medically qualified. Determining both manner and cause of death falls very clearly within the expertise and responsibility of the forensic pathologist. The “manner” of death might be, for example, that the victim was beaten around the head with a blunt instrument, while the “cause” of death may be blood loss. However, this is an area where the partnership between pathology and anthropology can work in harmony. Sometimes bones will tell us not only about who the person was, but what may have happened to them.

We ask different questions when dealing with the manner and cause of death. Does this child have too many old, healed injuries for them to have been caused by anything other than abuse? Did that perimortem fracture happen because this woman was trying to defend herself?

Experts learn to read different parts of the body for their own purposes. A clinician will look to the soft tissues and organs for signs of disease and a clinical pathologist may examine biopsies of tumours or categorize changes in cells to establish the nature or progression of a pathology or condition. The forensic pathologist will focus on the cause and manner of the death while the forensic toxicologist analyses body fluids, including blood, urine, vitreous humour from the eye or cerebrospinal fluid to determine if drugs or alcohol have been consumed.

With so many scientific disciplines all focusing on their own niche, sometimes with unblinking myopism, the bigger picture can often be obscured. For the clinician and the pathologist, the bones might be just something to crack open with pincers or electric saws in order to get to the organs inside. Only if there is trauma or obvious pathology will they be given more than a cursory glance. Forensic biologists are more interested in the cells that hide in the spaces within the bones than they are in the bones themselves. They will slice the bone and grind it down to a powder to get to the nuclear coding hidden in its depths. The forensic odontologist gets excited by teeth, but perhaps less so by the bones that hold them.

So the song of the skeleton may go unheard. And yet this is the most durable component of our bodies, often lasting for centuries, keeping its memories safe for a long time after the story told by the soft tissues has been lost.

If identity can be established from DNA, fingerprints or dental matching, nobody is much interested in the bones until all the other work is done and the experts have moved on to pastures new. It may be months, sometimes years, after a body is found before the forensic anthropologist enters the picture and the bones are at last called upon to give up their memories.

The scientist has no control, of course, over what they have to work with. The more recent the remains or the more complete the skeleton, the more of the story we can hope to recover, but unfortunately, human bodies are not always found intact or in good condition. The passage of time metes out its ravages on a discarded, concealed or buried corpse. Animals consume and destroy bones and the physical effects of weather, soil and chemistry conspire against retention of the song of a life lived.

The forensic anthropologist must be able to try to retrieve a part of its tune from just about anything, and to do that, we need to know what to look for and where to find it. If multiple bones tell a similar story we can have confidence in our opinion. If only a single bone is recovered we will necessarily need to be more cautious about how we interpret what it is saying to us. Unlike our fictional counterparts, we need to keep our feet on the ground and our heads out of the clouds.

Forensic anthropology is a discipline that deals in the memory of the recent, not the historical, past. It is not the same as osteoarchaeology or biological anthropology. We need to be ready to present and defend our thoughts and opinions in a courtroom as part of an adversarial legal process. Our conclusions must therefore always be underpinned by scientific rigour. We must research, test and retest our theories and be fully conversant with, and able to convey, the statistical probability of our findings. We need to understand and adhere to Part 19 of the Criminal Procedure Rules on expert evidence and to the CPS rules on disclosure, unused material and case management. We will, quite rightly, be robustly cross-examined. If our evidence is to be taken into consideration by a jury who will decide on the ultimate guilt or innocence of a defendant, we must be sound in our scientific understanding and interpretation, clear and comprehensible in our presentation and accurate in our protocols and procedures.

Perhaps forensic anthropology was once viewed as one of the easier routes into the interesting world of forensic science. It certainly exudes the kind of investigative charm that makes it irresistible to crime fiction. Not any longer. It is a profession, governed in the UK by a professional body with a royal charter. We must sit examinations and be retested every five years to remain active, competent and credible certified expert witnesses. There is no room in our business for the amateur sleuth.

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From WRITTEN IN BONE: HIDDEN STORIES IN WHAT WE LEAVE BEHIND by Sue Black. Copyright © 2021 by Sue Black. Reprinted by permission of the publisher, Arcade Publishing. 

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