Murder Most Florid

by Mark A. Spencer

  At each site, I would draw up a sketch plan and list the plants present, as well as the faeces and litter. The sketch maps would be drawn up using mapping software and the other information compiled into a database. To get an understanding of change, we had to resort to an old series of black-and-white photographic aerial images taken of London some 20 years earlier. Not only did The GLA Habitat Survey generate excellent information on the state of the capital’s natural world, but it also provided important information used in planning applications and strategic planning by London’s borough authorities. Sadly, it was later scrapped.

  Now I use a very similar approach to inform my assessment of changes in the landscape when doing forensic work. The huge advances in technology mean that it is possible to draw upon a wealth of online mapping tools, street views and aerial imagery to assess change. The resolution of many of these images is sufficiently clear that I am often able to identify not only individual trees and shrubs, but the species they are likely to be. These images and street-view images are very helpful in developing a pre-scene visit understanding of what I am going to encounter. I can start to identify areas of interest that I would like to examine in more detail or draw up a preliminary list of the plant species present. This can be very useful in guiding my response to the police and the forensic companies I work with.

  As helpful as these images are, they are no substitute for examining the plants directly. Non-botanists are often amazed that apparently identical plants are not the same species. An example of this are birch trees. Most people are familiar with birch; their silvery white stems are easily recognisable and found widely in our gardens, woods and heathlands. Many of us are so familiar with the word birch, that it hardly registers that this single word describes about 100 different tree species worldwide. There are two native species of birch (B. pendula and B. pubescens) found in our lowlands and a scarce, dwarf mountain species (B. nana, nana means small) which is largely confined to the Scottish Highlands. Things get more complicated in our gardens. Alongside the native lowland species, several other introduced species are also grown. The only way some of these species can be identified with confidence is to carefully examine their leaves and the fruit embedded within the catkins. Birch are widespread trees, common both in the wild and in gardens. Their leaves seem to get everywhere, as do their fruit and catkin scales and they are all quite often found in exhibits I examine. The fruit shape of birch is roughly the same outline as a hand-carved wooden fleur-de-lys. Each species is rather similar but also distinctly different in form, as if a different carver had created them. Identifying the fruits when they are embedded, and often badly damaged, in someone’s footwear and far from the tree that they came from can be quite challenging. As a consequence, I may need to retrieve samples or take photographs of birch fruit from a deposition scene for later comparison when I am back in the laboratory.

  Although I am not professionally trained as a forensic anthropologist, I have assisted in the retrieval of human remains. Under suitable professional supervision I hasten to add! It surprises people that a botanist would be assisting in this work. Part of the reason I assist is simply that the more eyes on the job, the better. If I see a bone, I’ll call out to the anthropologist (or archaeologist) and let them know it’s there. From a distance, all a listener would hear is the quiet calling out of ‘cervical vertebra’, ‘scaphoid’ and the other smaller bones of the body as we proceed. A place marker will then be added. Some bones, such as the smaller ones of the fingers and toes, can be very hard to find in dense leaf litter, in a wood, in December at twilight! Many a small partially decayed and decorticated twig or stone gets picked up momentarily in the anticipation that it is a weathered bone. One of the bones that can be particularly hard to find is the hyoid. This bone is unusual in that it is not in intimate connection with other bones; it is attached to the complex array of muscles that control the floor of the mouth, tongue, larynx, epiglottis and pharynx. It can also be of special interest or evidential value in some murder cases where strangulation is suspected, as a broken or damaged hyoid may be indicative of a ligature or throttling by hand.

  Finding bones at a deposition scene can be harder than you may imagine, especially if the person was not buried (or if the grave is very shallow). In these cases, the remains can be disturbed by animals, natural movements of the earth, flood events or accidentally by people through digging (such as road works). Disturbance means that it can be necessary to search over a very large area to find all of a person’s remains. Probably the most common cause of disturbance is by animals. They eat us.

  For many of us, now highly urbanised, the idea that we can be food for other organisms is repulsive and horrifying. From the moment we die, we become a rich source of nutrition. Complex microbial communities within our digestive tract and our skin start to digest us. Especially if we are outside, within minutes of death we are found by flies and beetles, and they lay their eggs on us. We are also food for a wide range of other organisms, particularly birds and mammals.

  I quite regularly lecture in public, recounting some of my experiences in forensics. I often talk about how I once worked on a case with a researcher who had conducted some fascinating reserach into the predation habits of birds and animals on human remains. She explained that, owing to the practical restrictions of being on a relatively small and very densely populated island, namely Great Britain, it was not possible to use human bodies for this work. Not entirely surprisingly, some people do not feel comfortable having human corpses near their homes. Therefore, it was necessary to use dead pigs as proxies for people. Apparently, pigs are suitable because they are a similar size and weight and have comparable fat density to humans. Forensic entomologists also use pigs as proxies for the research into the post-mortem interval. She asked me a simple question ‘Which animal or bird is the first to start feeding on the remains of a large animal lying dead on the ground?’. I ask the same question when I tell this story when lecturing. Not surprisingly, birds and mammals like foxes, badgers and crows are regularly mentioned. I, like most of my audiences, didn’t get the answer. It’s the wood mouse (also known as the long-tailed field mouse, Apodemus sylvaticus). Apparently, those cute little fluffy-whiskered critters of our woods and hedgerows are rather partial to a meat snack.

  My colleague and I spent quite a lot of time looking for human remains dispersed by foxes. They pose one of the more significant challenges encountered when examining a deposition scene. Most of us tend to think of ourselves as somehow apart from or different to nature. When we are dead, this false barrier breaks down. Human remains make fine pickings for scavenging animals like foxes. Luckily, like humans, foxes have behaviours that we can learn about and then predict. Foxes tend to remove a portion of the human remains, usually the extremities, and carry them to their den or a safe place. They are wary animals and are avoiding predation themselves. This means that, in most cases, the fox will have carried their food in a particular direction. Once that direction has been discovered, it is usually possible to retrieve what has not been consumed by the fox. Many people will find this the idea of being eaten by mice and foxes challenging and unsettling, but these behaviours are simply nature. We do our best to retrieve as much as possible; there may be evidence associated with the dispersed remains and clearly it is desirable to return as much as is possible to family members and friends.

  Working in forensics and with other experts has certainly helped me see our landscape and natural world in a very different way. Some years ago, I was working on another gangland murder case. We were looking for the victim of a so-called punishment beating that went ‘too far’. The police asked me to assist in searching an area of woodland next to a large house. The house had already been searched without any success and the police needed to widen their efforts by searching the wood. When I arrived, the police had identified several areas within the woodland that they thought were likely locations for a clandestine burial. The woodland was dominated by tall be
ech trees and as I walked into one of the clearings beneath the trees, I was immediately struck by why the police had prioritised it. The space was about the size of a large school classroom and most of the vegetation was low growing. The clearing was secluded from the road, and any views were blocked by a dense three- to four-metre high growth of cherry laurel (Prunus laurocerasus) and holly (Ilex aquifolium). Both plants are evergreen, meaning that they retain their leaves all year round; this makes them ideal for clandestine activity, particularly in winter when cover is limited.

  Within the clearing, none of the thinly scattered plants were more than a metre high, and much of the ground was covered by a thick mat of ivy. The space seemed perfect for disposing of a body, being secluded but with enough open ground to work without hindrance. The police were very excited by the location. Finally, they thought they had the right spot. Initially, I shared their enthusiasm, but this gradually diminished. The more I looked, the more I was convinced that the area had been purposefully cleared at least two years before the murder had occurred, and that since then nothing had disturbed the vegetation. I decided to wander around the wood to get a better feel for the vegetation. I came across several other open areas in the wood with similar dimensions and vegetation characteristics. They all appeared to have been cleared at the same time, probably with the intention of improving the habitat. Most likely, the shrubs in the clearances had been coppiced by people with woodland conservation in mind.

  I returned to the main location, my confidence growing that we would not find the victim here. Even though the area was large enough to hide someone’s remains, I couldn’t find anywhere that was large enough to dig without disturbing the scattering of small holly bushes that were dotted about. The bushes were sufficiently small that I wondered whether some were seedlings, but on closer inspection it was clear that all the plants had been coppiced. They had been cut to the ground and had regrown, therefore most of them were once larger and considerably older than they appeared to us as we stood before them..

  I explained to the CSM that I thought they were going to be unsuccessful and that the holly bushes were simply too old to have been moved without significant disturbance. He looked puzzled and asked me how that could be so; after all, they were small so they must be young? I remember having a small moment of realisation – I really did see the world in a very different way to many other people. I encouraged him to get down on his hands and knees and feel the base of the stems of one clump. After hesitating, he obliged. To this day, I still find it amazing how reluctant people are to look carefully at plants. Each stem was only one or two centimetres in diameter but were attached to a much larger stump that measured several centimetres across. I could see the realisation creep across his face − the original plants had been cut down and these shoots were the regrowth. The plants were indeed considerably older than they looked.

  While I was looking at the holly bushes, I noticed something about them that I’d never noticed before. Holly doesn’t have distinct buds like most other trees and shrubs growing wild in this country. Common trees like oak, birch or beech have distinctive over-wintering buds that leave a small ring of scar tissue behind once the shoot grows in spring. The easiest way to see this scar tissue is to look at the opening large sticky buds of horse-chestnut (Aesculus spp.). One of the forensically useful aspects these patches of scar tissue where the buds once were, is that they can help estimate the age of a branch or a sapling. Basically, start at the shoot tip and move downwards, each time you pass a ring of scar tissue, add another year. Any branch or sapling hanging over or growing in proximity to the deceased thus becomes a helpful means of estimating the minimum time period that the remains have been in position. It’s a very handy and quick way of providing an initial estimate of age.

  The absence of seasonal buds in holly presented me with a problem, how would I estimate how old these plants were? I spent a while pondering my problem and quietly observing. Getting to know a plant is key to understanding it. When teaching plant identification skills, I often advise botany students to spend time simply looking at the flowers, foliage and stems of a plant, ideally with a hand-lens, before jumping to conclusions about the plant’s identity. It is all too easy to get fixated on the larger, more obvious features such as flower colour and overlook the important ones.

  As I gazed, the penny dropped. Not all the leaves were the same size. At the tips of the shoots, the leaves were smaller; as I moved down the shoot, they gradually got larger and then they started to shrink again before once more getting larger. This pattern was repeated down the stem. I realised that, because of the cold and lack of sun, holly leaves get smaller towards the end of the growing season. As winter closes in, the shoot stops growing before resuming growth in the spring, and as summer approaches the leaves once more get larger.

  I had my means of estimating how old the short holly bushes were. I tried out my new approach on all the bushes in the area. They consistently showed the same pattern of growth and supported my assessment that they were too mature to support the idea that a burial had occurred in the space occupied by them. I called the CSM over to explain my observations. He was quietly agog and initially disbelieving, but the more I showed him the plants and explained my reasoning, the more I could see the hope fade in his eyes.

  As is often the case, the police felt compelled to continue with their search. I’ve come to accept this. All too often, even if an individual gets it, the laws of group behaviour kick in and the collective proceeds down familiar paths. Us botanists with our strange ways are a bit too much for some. The police and I surveyed the ground which was covered by an expanse of common ivy. On the ground, the stems of ivy are long and sinuous; they cover the soil in a fairly thick mat. Once again, I was convinced it would be impossible to wield a spade and cut through the stems without leaving signs of damage, of which there were none. After continuing to look for a little while, the police eventually became convinced by my observations and called off the search.

  To this day, the police have never found the man. A few months after my work with them, they received information from the criminal fraternity suggesting that the man never got as far as the woodland. After being killed, his body was placed in an oil drum, sealed with concrete and then thrown in a very large lake.

  10

  Fragments

  Hunting for the dead and examining their remains are certainly the aspects of criminal investigations that most capture the imagination of the public. However, most forensic work also involves slow and painstaking examination of exhibits. This work may not have the overt thrill and intrigue of an active crime scene, but it is where many of the real discoveries are made.

  Examination of exhibits takes place in anonymous buildings scattered across the industrial estates of this country. These buildings are nothing like the brooding, atmospheric laboratory sets of many crime-scene dramas. They are very well lit and usually sparsely furnished. There is a simple reason for this. It is vitally important that nothing is lost and that every action is carefully documented. The management of this work is very time consuming and requires a great deal of concentration. The movements of exhibits within these buildings are tightly controlled. This control is extremely important, because if there is more than one crime scene associated with an investigation, then exhibits from those two locations should not be examined in the same laboratory space at the same time. The same applies for exhibits linked to victims and suspects. Preferably, they are examined on different days. Barristers are adept at pointing out that examinations were done on the same date, thus casting doubt in the mind of the jurors that the work was done separately and securely. Every single action must be recorded and documented. Poorly recorded activity can be disastrous in court and could potentially lead to miscarriages of justice.

  I often need to examine footwear that has been retained as an exhibit by the police as part of an investigation. The footwear will be removed from the secure and restricted-entry evidence sto
re. A suitable laboratory space that has been cleaned prior to use is then allocated. Benches are wiped and swabbed with alcohol. A sheet of disposable paper is then placed on the bench. Before opening the exhibit bag, I will read and check all the label information to ensure that I am examining the correct exhibit. I, or one of the laboratory’s forensic examiners assigned to work with me, will then photograph the bag and the anti-tamper seals before opening the bag. The footwear will then be carefully photographed from all angles before I start to remove vegetation fragments. As I remove them, I will record where on the shoe they came from. Each individual fragment or batch of fragments will be photographed and put into packets. They will then be assigned subexhibit numbers. The numbering can get rather complicated. On completion of the work, the footwear will be returned to the exhibit bag and resealed. The seals must be signed. I really hate doing this bit, as the sealing is usually done with package tape which is a horror to write on. The same process also needs to take place for the subexhibits, and their creation documented. I often end up with a small dance going on in my head about how many subexhibits I really need and what their value will be.

  There is a hierarchy to the sequence of exhibit examination. Work to isolate human DNA or gunshot residue happens first. The aim of this is to prevent the possibility of cross-contamination with DNA or gunshot residue from outside sources. There are stringent regulations on how exhibits that may harbour human DNA are handled and stored, and the forensic examiner who works alongside me has overall responsibility to ensure that the correct procedures are followed. Being a botanist, I have not worked with human DNA, but I am mindful of the risks of cross-contamination. My PhD research was based on extracting DNA from water-inhabiting fungi, and I know how easy it is for DNA cross-contamination to occur if appropriate quarantine procedures are not adhered to. It’s frustrating if a PhD student gets algal and bacterial DNA in a fungus DNA sample; it’s potentially catastrophic if contamination occurs in a forensic setting. Consequently, I and the people I work with are very mindful of this every time we work on material in a laboratory. To date, similar regulations do not apply to non-human DNA, but I suspect they will do in the future, especially when evidence derived from environmental DNA (eDNA) and the necrobiome (the community of organisms that live on and within us after our death) becomes used in criminal investigations.