Murder Most Florid
Page 15
Generally, there are adequate treatments for most toxic plants and fungi found in these islands. There are exceptions, one of which is the deathcap (Amanita phalloides). The inherent danger of this fungus is rather given away by its name. You stand a very high chance of dying if you consume enough of this fungus, even with modern treatments. One of the reasons that deathcap is so awful is that the most toxic compounds, of which the amatoxin α amanitin is the most powerful, are thermostable – cooking does not break the molecule down and it remains active. Apparently, deathcap tastes quite nice, so you’re unlikely to spit it out while eating it. Unfortunately, by the time symptoms develop, typically about twelve hours after ingestion, the person is already in trouble. It can take several days to die of deathcap poisoning, and as the toxins work their way through the body the victim may appear to be recovering only to finally be felled by the constant onslaught of the almost indestructible α amanitin.
Thankfully, poisoning by deathcap is very uncommon. However, each autumn one of my mycological friends is on standby awaiting calls from hospitals relating to accidental poisoning by various fungi. The lucky chap on occasion receives stomach contents couriered to him in the depths of the night. He then needs to sort through the goo and examine the fragments under a microscope to identify the fungus. While I’ve not had to sit waiting for the courier at two in the morning, I have received samples of stomach contents from recently deceased people. My role is simply to identify the plant fragments. I can go no further than that, because I’m not a toxicologist and have no medical training. My observations will be passed on to someone more suitably qualified who will ascertain whether the plant material I have identified was the cause of death.
The natural world is a powerhouse of toxicity. The botulinum protein derived from the bacteria Clostridium botulinum is the most acutely lethal known toxin, and the deathcap and its charmingly named relative the destroying angel (Amanita virosa) live up to their names. There are many poisonous plants in our landscape and gardens, but most are totally safe to handle. The castor-oil plant (Ricinus communis), a commonly grown summer bedding plant and source of castor oil, is also the source of one of the most notorious toxins known to man, ricin. The Bulgarian dissident writer Georgi Markov was assassinated by an agent of the Bulgarian Secret Service using ricin. Markov was waiting for a bus near Waterloo Bridge in London when he felt a sharp sting in his right thigh. As he turned around, he saw a man picking up an umbrella, who then proceeded to hurry away. Markov died four days later in hospital. A post-mortem examination of his body revealed a small metal pellet, less than two millimetres across, in his thigh. The pellet, which had tiny holes drilled into it, had been filled with ricin.
About ten years ago I was extremely lucky to be invited to the Black Museum at New Scotland Yard. It is one of the most extraordinary places on the planet, full of exhibits and memorabilia originating from some of the most notorious crimes in our recent history. Among the profusion of ropes, guns, cleavers and other ghastly instruments of death, sits the tiny silvery coloured platinum and iridium pellet that killed Markov. It looks almost gem-like on its mount.
The museum is full of incredible and often very disturbing objects. One of the most captivating objects is the top of the skull of a man murdered by his former lover. As I remember it, at some point towards the end of the 19th century, the young heir to a wealthy family fell for a maid in the family household. Their relationship was discovered by the man’s family and the maid was expelled from the house, pregnant. Sadly, owing to her poverty and pregnancy, she had no option but to resort to prostitution to survive. Many years later she had established herself in her new profession when she received a fresh client. It was her former lover and, appallingly, he failed to recognise her. Engulfed with rage and a desire for revenge, she arranged for him to be murdered next time he visited. After the deed was done, she and her accomplice decapitated him and had his skull mounted in silver and fashioned into a goblet. For years after, at the end of each long working day, she would pour red wine into his skull and drink to her vicious victory.
One of my early childhood memories was of my mother placing a pile of tomatoes on the table and telling me that my father had collected them from the nearby sewage works. I was fascinated by the idea that the seed had travelled through someone’s insides and had subsequently germinated. I don’t remember feeling any aversion to the idea of eating something that had originated in this manner. In hindsight, it probably indicated that I was cut out for this job. Exploration of stomach contents is not only an important tool when assessing the probability of poisoning. Stomach and intestinal tract contents can also be very useful in identifying the last meal a person consumed and estimating how long someone has been dead (the post-mortem interval). In the United States, two researchers, Jane Bock and David Norris, have undertaken pioneering work examining and identifying plant fragments found in the digestive tracts of the deceased.
Certain plant tissue types are very tough and can withstand the grinding of our teeth, the acids in our stomachs and the enzymes that permeate our digestive tract. Many are so tough that they come out the other end partially or fully intact. On top of this durability, many of these plant tissues have distinctive morphological features that allow some vegetable components of the deceased’s last meal to be identified. It is possible to identify commonly eaten food such as potatoes, beans, cabbages and tomatoes from their mashed-up remains.
The infamous murder of ‘Adam’, a young boy whose mutilated torso was discovered in the River Thames in London on 21 September 2001 is largely remembered because of the very strong evidence linking his death to a ritualistic killing known as muti. Adam has never been identified, but his DNA and the mineral composition of his bones strongly suggested that he originated from near Benin City in Nigeria. This knowledge about Adam’s origins was vital. Careful examination of Adam’s stomach contents revealed that, shortly before his death, he had been given a meal containing 19 plant species, including beans. The remains of the beans from Adam’s digestive tract were identified by examining the outer shell, or testa, as it’s known botanically. In many plant families, the arrangement of the cells on the surface of the testa is very distinctive and can be used to identify the plant consumed. In Adam’s case, the testae were identified by a plant anatomist from the Royal Botanic Gardens in Kew as originating from the Calabar or ordeal bean (Physostigma venenosum). The work at Kew would have been greatly hampered if the police had not known of Adam’s origins. Worldwide, there are thousands of members of the pea and bean family (Fabaceae), searching the whole of the planet’s legume diversity would take a lot longer than focussing on one specific region.
The Calabar bean originates from tropical Africa and has long been associated with traditional beliefs, including the identification by ordeal of people believed to be witches. Suspected witches were forced to drink a concoction made of the bean and if they died, they were considered guilty; if they lived, they were deemed innocent. The police believe Adam was given Calabar bean as a means of immobilising him prior to his throat being cut. His head and limbs were then cut off. The active ingredient in Calabar bean is physostigmine, which affects the neural signalling to the muscles, resulting in seizures, salivation, loss of bladder and bowel control and, with a large enough dose, death by asphyxiation or cardiac arrest. Despite its fearful reputation, links with witchcraft and Adam’s tragic death, therapeutic doses of physostigmine have been used to treat glaucoma and as an antidote for poisoning by deadly nightshade (Atropa belladonna) and thorn-apple (Datura stramonium). Curiously, Adam had also been fed with thorn-apple, a plant with a fearsome reputation for its toxic and hallucinogenic properties. The thorn-apple belongs to a plant family that has regularly played a part in poisonings − the tomato family, Solanaceae. Solanaceae is full of very toxic species, including deadly nightshade, tobacco (Nicotiana tabacum) and mandrake (Mandragora officinarum). There are also a host of economically important edible plants in the family
– tomato (Solanum lycopersicum), potato (S. tuberosum) and sweet pepper (S. annuum) are some of the most well-known.
Tragically, Adam’s killers have never been brought to justice but there is always a chance that they may. At that point, the thorough work of the forensic specialists such as the researcher at Kew may play a central role in their conviction. There is also the possibility that new techniques that were not available at the time of the investigation may help find his killers and secure their conviction.
13
The Future of Environmental Forensics
After more than a decade of austerity, it is fair to say that policing and crime-scene examination in this country face challenging times. Public-spending cuts have had a very significant impact upon resources and, in my experience, have led to an increased unwillingness of the police to commit to specialist forensic services. It also appears immensely difficult for forces to provide training for their staff on specialist fields such as forensic botany. Without this training it is very hard to see how a crime scene manager, PolSA or a detective would consider using techniques which, in many cases, they may not have an understanding of, or may never have heard of. As police forces find it harder to fund specialist forensic examinations there is a knock-on effect; without revenue from police forces, forensic service providers are less able to provide some specialist services. Over the last few years we have seen increasing concern about the viability of the private forensics sector in this country. Some companies have folded, and I suspect others may follow.
Our society has enormous expectations of our public services. The police are expected to behave to the highest standards, and rightly so. But it’s become clear to me that we also have some ludicrous expectations about how they should work. I’ve been horrified over the last few years to see the police being attacked in the tabloids and on social media for the temerity of taking breaks and eating while on duty. This sort of criticism is dehumanising and is born of entirely unrealistic and unachievable demands. Having spent hours crawling around on my hands and knees in the freezing cold with police staff, I have come to appreciate that, in the round, they deserve our praise. Clearly, corruption or poor procedures need to be challenged and dealt with, and, of course there are some bad apples. These are issues that are present in many of our national institutions and larger organisations. It is also apparent that there are institutional failings within our police forces that affect parts of our society disproportionately. However, I suspect that many failings are due to the underfunding of our police services. Over the last decade I’ve witnessed the efforts that people put into solving serious crimes and the increasingly tough constraints placed upon them to get the job done. The role that a specialist such as myself plays is relatively small, but I fear it may get smaller if we continue down the route we are taking. The police appear less prepared to commit valuable resources to explore avenues of investigation that they may be unfamiliar with, and while recent technological advances offer new ways of investigating crime, I am concerned that as investigators become more pressed for time, they will have fewer opportunities to explore these approaches.
One of the great challenges of working with the police is persuading them that an integrated approach to exploring the environment will yield the best results. Most areas of crime-scene specialist work are very much discrete entities. For example, the presence of gunshot residue is not dependent upon other forms of trace evidence such as glass fragments or fibres. This is very different to information gathered from the natural environment. Soil types can be strongly indicative of what plant communities are present, which in turn may predict what invertebrate, fungal and microbial assemblages are present.
The common rock-rose (Helianthemum nummularium) is a popular garden plant that tolerates a wide range of soils. In the wild, this relatively widespread plant is much fussier. Nearly all of its British and Irish locations are on calcareous soils over either limestone or chalk, except in some parts of Scotland where it is known to grow on acid soils, but even on these it’s still pernickety, as it will only thrive in sunny locations and on grassland that is many decades or centuries old. The common rock-rose also has a suite of other organisms in tow, some of which are entirely dependent upon the plant. In and around the roots lives a diverse community of fungi, including species of bolete, milkcap, webcap and fibrecap. Both the rock-rose and the fungi in these mycorrhizal associations, as they are known, benefit by exchanging food and nutrients. Feeding on the unopened flower buds and pollen is the specialist pollen beetle Meligethes solidus. Foraging on the leaves are four species of bug, one of which, Emelyanoviana contraria, is extremely rare and restricted to limestone pavement in Yorkshire. Limestone pavement is not street paving, it is a scarce natural habitat created by the erosional power of water. The larvae of several species of moth, including a leaf-miner Coleophora ochrea, also utilise the plant. Leaf-mining insects are extraordinary: they spend much of their lives burrowing within the leaf, eating the soft tissue between the upper and lower surfaces. Also, among the leaves is the fairly widespread beetle Mantura matthewsi, while the much rarer Helianthemapion aciculare is restricted to the Great Orme in North Wales and the very rare pot beetle (Cryptocephalus primarius) survives in few localities in southern England. Not surprisingly, there are also a wide range of other invertebrates like the beautiful silver-studded blue butterfly (Plebejus argus) that feed on the plant but are not entirely dependent upon it.
While giving some insight into the complexity of our ecosystems, this example also demonstrates that biological evidence gathered as part of an investigation should not be viewed in isolation. If I were presented with an exhibit that contained heavy clay particles and rock-rose pollen, I would most likely conclude that the sample came from a garden. However, if I received a sample with chalk particles, rock-rose pollen and the wing cases of the beetle Mantura matthewsi, I would most likely conclude that the origin was chalk-grassland. This example may be hypothetical, but it is not far from reality. I quite often receive material that may have both soil and non-plant biological components within. While I don’t consider myself professionally competent to characterise soil types or identify beetles based on their wing cases, my knowledge is sufficiently broad that I can recognise their potential evidential value in a case such as this and find someone who has the appropriate skills to identify them.
In two cases I’ve worked on, the need to view these biological assemblages as a whole was paramount. In one, a fellow museum biologist and I identified several very interesting organisms in an exhibit. Amazingly, there was a fragment of an extremely rare insect that is only found in one location in the whole of Britain and Ireland. This and other information led us to believe that it was extremely likely that the exhibit came from overseas. In the other case, a very violent rape and murder, the police simply refused to examine the environmental samples. In both cases, it was my view that there was a high likelihood that further scientific examination of the exhibits would reveal significant results. Frustratingly, in both cases the police refused to pursue these lines of enquiry. The last time I checked, both cases remained unsolved.
Several years later, these choices ‘not to pursue’ still frustrate me. It can be very hard not to get angry about decisions that you disagree with. I know this happens in all walks of life, but there is a particular sting when you are working on a murder inquiry. I don’t lose sleep and I am not haunted by these decisions but they certainly irk. One of the cases is now over 6 years old and the person’s family and friends continue to grieve without knowing who was responsible. I recently drove very close to where the badly decayed remains were found. As we drove, I mulled over the case and quietly cursed the decision ‘not to pursue’.
Usually, I am not party as to why the police choose to discontinue an avenue of investigation. There is no obligation on their part to explain their actions to somebody such as me. They may be required to justify their actions in court, and I may be called to explain my findings an
d subsequent advice. The motivations of the police in these cases is unclear, but I suspect the most likely cause is lack of money. I fear that insufficient training is also a factor. The natural world is complex, it takes time and experience to understand. The police, and CSMs in particular, need training in order to be able to understand when specialist disciplines like forensic botany or entomology may be of use. I have met people who work for UK police forces who have never previously heard of forensic botany. To me, this feels like there is a need for some introductory training in all aspects of environmental forensics.
The loss of public resource has been insidious and incremental. When I was still working for the Natural History Museum, I received a request to take on the unwanted herbarium of the Forensic Science Service (FSS). The FSS was a government-owned company that provided forensic science services to police forces and government agencies of England and Wales. The FSS herbarium had been compiled by FSS staff over a period of about 30 years and was used as a reference collection. At the time of the enquiry, there was no longer anyone in the FSS who had botanical expertise, and the facility in which the collection was housed was being handed over to another organisation. Either the NHM saved the material or it would go in a skip.
Sadly, I was used to this sort of request. Very often the families of recently deceased people would find collections and want rid of them. On one occasion, I was contacted by a schoolteacher who had rescued a very fine and significant collection of several thousand specimens collected in the Victorian era. The school had no interest in the herbarium, and they were going to throw it away. Sadly, such disregard for natural history collections heritage and their historic, cultural and scientific value is not uncommon. Herbariums are merely seen as ‘flower pressing’ and worthless. But often they may contain significant cultural and scientific information that enrich our lives and help us understand the world around us. Even though I’d not seen the FSS collection I felt it was likely to be of scientific and historic value, so I agreed to take a look at it. Unsurprisingly, it was not in a good state. The specimens were shoved into plastic bags and clearly in need of some curatorial attention. On behalf of the trustees of the Natural History Museum, I agreed to accept the collection and accession it into the museum’s holdings. Doing so would entail many hours work on the part of my team of volunteers and staff. The specimens would need to be assessed and any material that was beyond rescue would have to be discarded. The retained specimens would then be remounted on conservation grade paper (each sheet costs around 80 pence, depending on the price of paper at the time) and catalogued. Years ago, I calculated that a properly mounted and databased herbarium specimen costed about £7.50; no doubt the figure is higher now. The FSS herbarium consisted of several hundred sheets and they did not come with a cheque. The museum had to absorb the cost of saving this important material.