Written in Bone
Page 23
Our ability in this case to determine sex, age, height, shoe size and hair colour from the limbs alone, along with our assessment of the length of time the remains had been in the water, gave the police sufficient information to target likely matches on the missing persons database and identify the victim quickly. That in turn led to a swift apprehension of the perpetrator. The features that can be established from the limbs alone might not amount to conclusive evidence of identity in a court of law, but they can provide strong intelligence to focus the direction of an investigation. And they don’t always have to be real limbs.
One dark November night, police were called to a flat in an inner-city block in response to a report of shouting, screaming and breaking of objects that indicated a heated confrontation was in progress. When they arrived, they found the flat in utter disarray and a man lying on the floor of the living room. The paramedics were unable to save him and he was pronounced dead at the scene.
There was a lot of blood on the carpet, furniture and walls and clear signs that the victim had been beaten severely around the head several times. A postmortem examination confirmed that the cause of death was multiple blunt-force trauma to the skull, resulting in extensive blood loss.
I was tasked with examining the skull, reconstructing the pieces and attempting to establish what kind of weapon might have been used in the attack. With the first PM already having taken place, the broken sections of skull had been extracted, and the skull cap removed with a Stryker saw, to allow for examination of the brain and its coverings.
When bone is wet, as it will be when an injury is perimortem, and the trauma has been violent, the pieces will not always fit back together perfectly, especially when the bone in question is from the skull and the layers of diploic bone have split. So it can sometimes take hours of fiddling to try to figure out where almost unidentifiable little fragments were once joined. We use a type of heavy-duty superglue to bond the pieces of wet bone together and if you are not careful you often find your gloves welded to the three-dimensional puzzle you are trying to reconstruct.
The pressure on you to come up with the first two pieces that dovetail is immense as everyone in the room looks on in the expectation that you are somehow going to accomplish this reconstruction in the blink of an eye. Isn’t that what they do on the telly? Then slowly, usually once everybody else has lost interest and drifted away in search of tea and biscuits, you start to gain momentum as more and more pieces gradually come together. Only then can you start to interpret the trauma analysis that will allow you to determine how many blows occurred and in what order.
It was clear that this man had been struck around the head at least three times. The first blow was to the front of his head and the second and third to the left side, perhaps when he was already on the floor. They had been caused by a blunt instrument, probably made of metal as there were some sharp edges. There was a curved edge to one of the impact points that suggested something like a crowbar, but there also seemed to be a second, sharper, point of contact, more like the tip of a knife. So it was possible there had been two weapons, which didn’t make a lot of sense to us at the time.
The explanation, which we heard about from the police after the murderer was found guilty and had started his prison sentence, was so bizarre that I think we could be forgiven for not managing to pin down the murder weapon at the time of the postmortem examination.
The dead man, Michael, had been known to the police. As he had worked as a gay male prostitute, they had feared that tracking down who might have been at his flat that evening would be challenging. But Michael’s regular haunts were duly visited and his fellow sex workers questioned, and two of them mentioned a man they had not seen before. They said that Michael had gone off in his company at some stage that night, though neither could be sure exactly when. Their description of this man was fairly generic—until one of them happened to comment, almost as an afterthought, that they had jokingly dubbed him “the Captain” because he had a prosthetic right arm with a hook on the end. Apparently, his pub party trick was to take off his prosthesis and hang it from its hook over the side of the bar.
The police couldn’t believe their luck. Not only did they have a possible suspect who was known to use the services of male sex workers and to have a violent temper when he had been drinking, but he wasn’t going to be too difficult to find. “The Captain” was quickly located, picked up and taken in for questioning. He attributed his rages to the onset of PTSD after he was injured by a roadside bomb during his military service, which was what had led to the amputation of his hand and part of his forearm. His distinctive hooked prosthesis was removed for forensic investigation and blood matching Michael’s was found around the cup area of the limb, where the hook slotted into the wrist-based mechanism.
As well as the stainless steel hook at the end of the prosthesis, there was a finger-like tine that lay along its inner surface, apparently designed to increase its gripping capability. Forensic experts were able to match the hook and the barb-like shape of the tine to Michael’s skull injuries and confirm that the prosthesis was the most likely weapon to have caused them. In the wrong hands, artificial limbs can kill.
◊
Sometimes it is not so much the bones themselves that help us with identification as the joints between them. Like the bones, the joints in our limbs mirror each other: the shoulder is homologous to the hip (both articulating with a girdle), the elbow to the knee (at the intersegmental junction of the limbs, where the range of movement is limited) and the wrist to the ankle (where the long bones articulate with the terminal appendage of either the hand or the foot respectively).
These are all freely movable (synovial) joints but there are differences. While the hip and the shoulder can move in all directions (flex, extend, adduct, abduct and rotate medially and laterally), the shoulder has developed an additional ability to exaggerate movement into what we call circumduction. This means that we can swing our upper limbs around like a windmill, which is something few of us could achieve with our lower limbs, regardless of our flexibility. I dare you to try.
The downside of this increased mobility in the shoulder joint is a much higher risk of dislocation in the shoulder than in the hip. To have a hope of keeping us upright, the hip joint must be kept tight to bear our weight and must remain stable, whether we are standing or in motion.
The knee and the elbow are very restricted in their range of movement, especially the elbow, where movement occurs only in a single plane of flexion and extension, which is why these are known as hinge joints. The knee has a little more flexibility, just enough to enable the femur and tibia to rotate slightly on each other to lock the knee when we are standing. This is a mechanism that assists in maintaining stable stance and the reason why you have that momentary collapse of balance when someone unexpectedly pokes you in the back of the knee.
The wrists and the ankles are largely comparable, with a range of movement that allows our hands and feet to adopt a variety of positions, in keeping with their respective primary roles of manipulation and locomotion.
Our joints take a fearsome amount of strain from repeated use over our lifetime, and nowadays can be routinely replaced or resurfaced. Over a quarter of a million joint replacements are undertaken on the NHS every year. Hip and knee replacements remain the most common, but shoulder, ankle and elbow replacements are on the increase. These surgical procedures leave their mark on the skin surface in the form of very typical scar patterns in specific locations. And in parts of the world where such procedures are subject to strict legislation, there is usually a requirement for any implant to carry a unique reference number, which should be recorded in the patient’s medical records. So when we come across these, they should be fairly easy to trace. But life is never that simple.
There is no global register of such information and in countries where medical tourism is in the ascendancy—the top three for joint replacements are India, Brazil and Malaysia, where the cost
is low and availability swift—records can be far from complete. A hip replacement carried out privately overseas may never appear in a patient’s NHS records, and tracking down the hospital where it took place will be extremely difficult. In less scrupulous corners of this blossoming worldwide industry, where the supplier may not even provide their implants with unique number identifiers, many of them have been known to carry the same number, which makes identification pretty much impossible.
The ability to identify artificial hardware, and related scar damage to its host, is a necessary part of the modern forensic anthropologist’s skill set. The dissecting rooms of most anatomy departments have a box of various orthopaedic implants extracted from bodies donated for dissection which are retained to teach students to recognize these objects if they come upon them, perhaps among decomposed remains. Other ironmongery associated with broken bones and surgical interventions includes plates, screws, wires, pins, rods, nails and washers. Sometimes cataloguing what we find can seem more like a DIY-store stock-take than an assessment of orthopaedic surgical attention.
It is critical that artificial bits and pieces introduced into the body are understood just as well as its natural components. This foreign material tells us what kind of medical treatment the person may have received, and that may be key to establishing who they were or what may have happened to them.
It is not surprising that long bones are prone to fracture as they are the means whereby we interact with our environment. So it is important to check medical histories where possible. Previous healed fractures or the presence of orthopaedic implants are a good indication that medical records are worth trawling through. It has just crossed my mind as I write that my father’s hip replacement has probably ended up in a box at the funeral director’s office, perhaps in the same one as my mother’s replacements for her big toe joints. How odd to think that parts inserted into both of them may have ended up in the same jumbled box of spares. They were both cremated and, as these implants do not burn, they must at some point have been extracted by the undertaker. I never thought to ask.
As we have seen, fractures can play an important role in the intelligence and evidence gathered from a postmortem examination. So a forensic anthropologist must be able to determine whether they occurred before, during or after death. Premortem fractures do not usually have any connection with the death itself, except, in some instances, as evidence of the possibility of past abuse. They can often be linked back to medical records, and the time in the person’s life when they happened can be estimated from the degree of healing and callous formation that has taken place. Postmortem fractures may also be inconsequential to the death, although they can help us to build up a picture of the methods used to dispose of, or conceal, a body. So it is perimortem fractures, those which occur around the time of death, and which may be related to the manner of death, that tend to be of greatest intrinsic forensic value.
What are the sorts of injuries that result in our long bones breaking? The humerus is not a bone that fractures very often, but when it does, it is usually due to a fall or a sports injury. Because the radius and the ulna are connected by a membrane (interosseous membrane), if one bone is fractured, the other may follow suit. Fracturing of the radius is frequently the upshot of a fall on to the outstretched hand, when the impact of the ground on the heel of the hand will be transferred up the radius and across the membrane to the ulna. This is known as a Colles’ fracture, named after Abraham Colles, a noted early nineteenth-century Irish professor of anatomy, who wrote a treatise on the subject, and it is particularly common in falls among the elderly, whose bones are more fragile and may be weakened by osteoporosis.
The radius and the ulna are also sites we examine for defence fractures. If someone is raining down blows on your head, you are likely to raise one or both of your forearms to try to deflect the assault, which often leads to fracturing of the shaft of either the radius or the ulna or both. This was one of the injuries we saw in Harry, the little boy who died at the hands of his father, in Chapter 4. In these circumstances the break will be in a different place from one caused by a fall, and so it can be pivotal in distinguishing between an accidental fall and a criminal attack.
Postmortem fracturing of the radius and the ulna is commonly seen in those who have died in a fire. As the muscles respond to the intense heat, they contract quite extensively and the body assumes a pugilistic pose, with the limbs flexed and the fists clenched. The strain on the sites of muscle attachment can eventually fracture the bones at the wrist, especially if they are further weakened by fire damage. Identification of fragile, burned bone fragments is a very specialized skill and these will need to be retrieved before the scene can be cleared of debris.
The task of recovering the remains of one elderly gentleman who died in a house fire we attended was typical of what we encounter. He had lived alone and was known to like a smoke and a drink, and the police and fire service were reasonably confident that there were no suspicious circumstances.
In buildings where a fire has taken place, the electricity will usually have been turned off for safety reasons and so you will probably be working with battery-operated lighting, unless a generator has been brought in. You will also be wearing a face mask and goggles and navigating a monochrome moonscape of various shades of black and grey. The floor is likely to be covered in debris, especially if the ceiling, and sometimes the contents of the floor above, have fallen through. None of which makes it easy to locate tiny fragments of charred bone. The man had died in his armchair in his sitting room, surrounded by piles of newspapers and several whisky bottles, many of them containing urine. The ceiling had collapsed on top of him. The fire officers believed that the seat of the fire was in the vicinity of his chair, and so it is likely that a cigarette was the source.
As human bodies are made up of so much water, they do not burn terribly well and what we mostly see is scorching of the skin, especially where clothing has caught fire. Areas of the body that are uncovered tend to fare the worst, usually the head, hands and sometimes the feet. In this case, the man’s feet were less damaged than they might have been because his slippers had melted around them, protecting them to some extent.
His wrists and forearms were more badly affected. It was the height of summer, and he had probably been wearing a T-shirt which left them exposed to the fire. We could see that the fire damage and trauma caused by muscle contraction had resulted in the fracturing of his radius and ulna, and although parts of his hands were still attached to the long bones, some of his finger bones were missing. Exactly which ones had to be established at the scene because it was our responsibility to find and collect them.
It takes many years in this job and a thorough knowledge of anatomy to be able to recognize burned fragments of bone, some no bigger than the nail on your little finger, and to assign them accurately to a particular part of the body. But it has to be done, because you absolutely cannot have body parts left behind to be stumbled upon later or, even worse, thrown out with the burned debris from the house when it comes to be cleared.
First of all the body had to be lifted from the melted armchair and removed from the room. This is not easy when the fabric of the chair has melded with parts of the body and you have to cut away remnants of fabric or foam padding to free it. Fire victims are often rigid and fixed in their boxer’s pose, which makes them awkward to lift and to secure in a body bag designed to accommodate a supine figure with limbs extended. But once the victim has been extracted and laid out on a body bag in the room, it is easier to examine the ends of the limbs and to determine where the postmortem fracturing has occurred and which anatomical parts remain unaccounted for.
Having compiled your inventory, you keep this in your head while you search the debris for what is missing. In this painstaking way, we managed to reunite this gentleman with all of his fingers and the lower parts of the long bones of his upper limb, which were transferred to the mortuary with him in the body bag.
<
br /> Femora, as has been discussed, are often fractured in car accidents, when knees are rammed into the dashboard of the vehicle. The bone is also commonly fractured in the elderly as a result of bone loss through advancing age, which makes hip fractures another hazard for older people. These can be caused by something as innocent as turning over in bed. Somewhere between 70,000 and 75,000 hips are broken every year in the UK, 75 per cent of them in women with an average age of almost eighty years. The link between hip fractures and mortality is strong. Did this person fall because their hip broke, or did they break their hip when they fell? In these cases, trying to say for certain whether the injury was premortem or perimortem can be very difficult.
My father broke his hip after he was admitted to a psychiatric hospital because of his advancing Alzheimer’s. He was unstable on his feet at the time and the nurses were comfortingly honest when they told us that they could not be sure whether he had tripped or whether one of the other patients had knocked into him or pushed him. If you cannot tell the difference between the two in the living, it is no surprise that it can be almost impossible to be certain in the deceased.
The kneecap, or patella, is the biggest sesamoid bone in the body. The term “sesamoid,” from the Latin for “sesame seed,” is usually reserved for small, nodular bones that develop in the tendon of a muscle. In the case of the patella, which obviously looks nothing like a sesame seed, it is a bit of a misnomer.
There is another sesamoid bone that might be found around the knee joint: the fabella (“little bean”), which can form in the tendon of the lateral head of the gastrocnemius muscle at the top of the calf. It is estimated to be present in fewer than 40 per cent of people and is more common in elderly men than in any other group. So when we come upon a fabella, it is worth finding out whether antemortem X-rays are available for comparison, as its presence may have some relevance in helping to identify the deceased. The function of the fabella is not well understood. There has been a suggestion that it is an evolutionary feature which has re-emerged, perhaps due to a combination of genetic and environmental factors. That theory seems more than a little farfetched to me, but then, I am not a geneticist.