Murder Most Florid Read online

  This book is dedicated to the plants and the dead.

  Contents

  Title Page

  The Phone Call

  1 Botany, Forensics and Me

  2 The Deposition Scene

  3 Becoming a Forensic Scientist

  4 Brambles and Buddleja

  5 Tales of Knives and Wood

  6 The Layby

  7 Grave Searches, Canines and Cadaverine

  8 Pollen and Spores

  9 Looking Anew

  10 Fragments

  11 The Curious Microscopic World

  12 The Case of the Scabby Ankle

  13 The Future of Environmental Forensics

  Acknowledgements

  Reading List

  Copyright Page

  The Phone Call

  Sitting at my desk, my eyeballs are gasping for colour and sustenance. The open-plan office is very grey and devoid of natural light. I’m rather bored and don’t feel particularly engaged with my work today, which is unusual because I have an amazing job. I am the curator of the British and Irish herbarium at the Natural History Museum in London. An herbarium is a collection of dried plants. It’s the sort of job that botanists would clamber over the flailing limbs of their competitors to get to. Nevertheless, I’m bored. It’s just one of those days.

  The phone rings and I pick it up expecting to speak to a colleague. But it’s not a colleague: the voice on the other end of the line is a crime-scene investigator. They ask if I am available to assist them with a potential murder enquiry. The very heavily decayed remains of a man have been found by the edge of a river. He has been identified and is believed to be estranged from his family. There are concerns that he may have been killed by a relative, but it is also known that his mental health was poor, so suicide can’t be ruled out. When discovered, the man’s body was partially covered by vegetation and the crime-scene investigator would like to know if I can provide an estimate of how old the plants are. They hope this information will help establish how long his remains have been at the location.

  As I ask some questions about the vegetation surrounding the body, it soon becomes clear the investigator knows almost nothing about plants. Equally, I know very little about crime scenes. I can’t draw upon television crime dramas for knowledge as I’ve never been a fan, unless they have Christopher Meloni in them, but that’s another matter. The investigator offers to send me some images from the ‘deposition scene’ and sensing I’m green, she warns me that the images are very graphic. I accept. At least they won’t be grey.

  She was right, the images are graphic. As the office is open plan, I take care to open the file so that colleagues cannot see what I’m looking at. Luckily, the desk dividers are high and I’m in the darkest corner of the room. No doubt my colleagues can hear my exclamation, but they take no notice; they’re used to my intemperate outbursts. The images are of the deposition scene, where the man’s body was found. There is lush vegetation along a riverbank, and it looks quite idyllic, except for the partially submerged shopping trolley and the man’s very heavily decayed body. He is partially clothed, but his clothing can barely be discerned because it is discoloured by his putrefied remains. His ribcage, spinal column, arms and partially de-fleshed skull are clearly visible. His teeth appear bared. They are not − his lips are no longer there, as they have been consumed by a diversity of organisms feeding on his remains. The nature of the decay is such that what remains of him is either dark charcoal grey or ash coloured and contrasts strongly with the late summer green tones of the vegetation surrounding him. I take in the images and await my reaction; will I be able to withstand this? I feel fine, which is a relief.

  I call the crime-scene investigator back, confirming that I can assist and make my arrangements to travel to the deposition scene. Before I leave, I go upstairs to visit colleagues; they are both forensic entomologists. The Natural History Museum is well known for its expertise in dinosaurs, but behind the closed doors are many other specialists who are world experts in their own fields. One large group of researchers and curators are the entomologists. They look after and study the museum’s vast collection of insects. My colleagues use information collected from insects to estimate how long a person has been dead; this estimate is known as the postmortem interval. I need their advice and in return they have a favour to ask. They need me to collect insect larvae from the body and the ground nearby. They explain to me how I need to collect the specimens and how they should be stored. Am I happy to do that? I say yes and they give me some personal protective clothing as I have none. One of them also gives me a little pep-talk; she is very experienced when it comes to working with the dead and has even worked at the body farm in Tennessee, a famous outdoor research facility where the donated bodies of the dead are studied in scenarios emulating murder scenes or disasters.

  On my way to the scene, I divert to a chemist and buy some surgical grade soap. I’m not particularly obsessive about hygiene but I’m starting to feel some anxiety about what I’m about to confront. It’s a long train journey and I attempt to brace myself for what I’m soon to experience.

  On arrival, I make my way to the local police station to meet the police officer in charge of the case, as well as the forensic scientist appointed to oversee my work. The officer explains to me that since my phone conversation the man’s remains have been removed. We then proceed to where the body was found. The area is a typical light-industrial corner of a small town on the edge of the Pennines. Behind the single-storey warehouses and lockups, there is a small river edged with surviving fragments of the pre-industrial landscape. Most of the dominant plants are native trees and shrubs but there is also an abundance of invasive non-native Japanese knotweed (Fallopia japonica), buddleia (Buddleja davidii; confusingly the scientific name is spelt ‘Buddleja’ whilst the English names are ‘buddleia’ or ‘butterfly bush’) and Himalayan balsam (Impatiens glandulifera). There is an officer stationed near the entrance of the site to keep the curious at bay. We climb over the fence and walk forward. Soon we can smell decay.

  When we get to the deposition scene, I discover that the police have cut down most of the vegetation and raked it into piles. Not a good start. Estimating the age of vegetation is largely dependent upon its being intact! The police officer removes the tarpaulin that covers the deposition scene. Although they have removed the man’s skeleton and personal possessions, a lot of his body tissue and stomach contents remain spread over the adjoining vegetation. The smell is almost overpowering. I try and take in the experience, without appearing inexperienced. The officer accompanying me explains that the police believe that the man’s body had been there for several months and that he had been submerged two or three times by floodwater.

  The smell is very intense. It is so strong that the officer tells me that, ‘This is the worst one I’ve had in seventeen years.’ I resist the urge to tell him this is my first case. In fact, I’m so determined to do the job properly and not appear naïve that I get on my hands and knees and start to examine the decaying flesh attached to the vegetation very carefully. Now, the smell is overpowering and in the back of my mind I can feel the compulsion to retch, but I withstand the urge and proceed with my observations. I am looking at the stems of the Himalayan balsam, or rather I’m looking at the bases of the ones that escaped the strimming. They are flattened against the ground and are partially covered in decayed human tissue. It appears that the man’s body was either placed or came to rest on top of the stems. At one point my physiological responses threaten to take control and I feel I may be sick. I stand up and breezily start a conversation with the officer. My strategy works, and the upwelling of nausea subsides, so I get back down on my knees.

  After finishing my botanic
al examination, I explain my findings to the officer, couching them with one major caveat, which is that the strimming and subsequent raking has rather damaged the vegetation – basically, I don’t have a lot to go on! However, the man’s remains were laid on top of the partially decayed stems of the Himalayan balsam, an invasive nonnative species that is an annual. Annual plants usually germinate from seed each spring, grow, flower and set new seed within one year or growing season. For example, the common wild plant, thale cress (Arabidopsis thaliana), a small member of the cabbage family (Brassicaceae) can complete its life cycle in less than six weeks. Himalayan balsam originates from the foothills of the Himalayas. Each spring after the last frosts, seed in the ground germinates and the young plants rapidly grow to a height of one or two metres before flowering and dropping new seed, until the first frosts of autumn, which kill the adult plant. Owing to its beauty, Himalayan balsam was introduced to British gardens in the 1830s and was established in the wild by the late 1850s. Since then it has spread rapidly because of its fecund nature; a metre-square clump of the plant can produce up to 32,000 seeds. It is particularly abundant by streams and rivers in the cooler parts of these islands.

  Based on my knowledge of the ecology, I estimate that the Himalayan balsam plants are about six months old. And it’s also possible to estimate when the man’s body flattened them. This can be done by examining the regrowth pattern of the remaining stems emerging from beneath his remains. I tell the officer that, based upon my observations, the man arrived at the location within the last two months.

  I explain that I’ll provide a full report of my findings, but before I go, I need to collect the entomological samples for my colleagues, whose careful instructions I follow to the letter. My colleagues had told me that once fly larvae have finished feeding, they move away from their food source and bury themselves in the ground to pupate. They do this to avoid getting eaten by other animals feeding on the remains. I collect soil samples from around the deposition scene in the hope that there are fly pupae in the samples. I carefully document where and at what depth each sample of soil is taken from. Once I finish collecting the samples, the officer very kindly offers to take me to the storage facility where the man’s personal possessions are being held. There are a lot of ‘maggots’ on his clothing that I can take to supplement the material I’ve already collected.

  We arrive at the anonymous police facility on an industrial estate. I don’t know whether it’s a reflection of our society’s changing attitudes towards policing or tightening budgets, but we now rarely place our police stations at the heart of our towns and cities. Often, they appear to be shoved away in the metaphorical dark corners of our communities. They have become utilities. I’m shown into a room with two or three cabinets designed to dry decayed and wet evidence. The smell is awful. Despite the room having air-conditioning, the stench is magnified and much more intense than outdoors. As I open the door to the drying cabinet, a wall of odour like burnt car tyres mixed with intense sweet sickly jasmine, assails me. The smell is partially made up of 3-methylindole, also known as skatole. Skatole and the related chemical indole, along with putrescine and cadaverine, are produced during decomposition of animal bodies. The officer backs out of the room and leaves me to it.

  In front of me are the last of the man’s personal possessions; his badly stained clothing is barely recognisable as garments. The fold and curve of his now absent torso and limbs are picked out by the staining. It’s very sad. For some reason it reminds me of the Shroud of Turin − I don’t know why, I’m not a religious man. I take hold of a pair of tweezers and start removing larvae and pupae from the clothing. They are quite hard to see so I need to get very close to the fabric to remove them and because of this, the smell intensifies as I drop the insects into sample vials. It’s not an ammonia-like smell, my eyes don’t water, but it is hammering into my nasal cavity; it feels like I am inhaling dense, liquid odour. Once I have collected the entomological samples I stand up, close the cabinet and gratefully retreat for fresh air. The officer hastily closes the door to the room, and I take my leave.

  As I head home, I feel very emotionally charged. I keep smelling rich jasmine-rubbery odours coming off me. I go into a train-station toilet and wash my hands vigorously with the surgical soap I bought earlier. Still, the smell remains. I’m also feeling slightly nauseous. I tell myself that this is largely an evolutionary response and that it’s natural to feel this way; the gag reflex evolved to ensure we eject toxic material and minimise potential harm. Nevertheless, I feel I need to tackle the sensation, and I’m hungry. For some curious reason, I decide I need to find a food that is some way emblematic of the decay I’ve just experienced. Short on options, I choose a potato salad, rich and runny with mayonnaise. I then get on the train and head home. I eat my meal very slowly and carefully, each mouthful accompanied by a swirl of thoughts and emotions.

  The smell continues to linger in my mind. Several days later, despite having showered and changed clothes, I can still smell that rich, cloying scent of decay. I know there’s nothing there, but I catch myself sniffing my forearms just in case I’ve missed a bit. My mind keeps running through my experience by the riverbank and I check that my conclusions are sound. I have a residual fear that I have missed something or that my observations are not correct. Could I do this again? Would I like to? Yes, I’m hooked already – it’s fascinating. Now, every time the phone rings in my office, I have a flutter of anticipation. Is it another case?

  1

  Botany, Forensics and Me

  It’s almost a decade since I forced myself to eat that potato salad. A lot has happened since. I no longer work for the Natural History Museum. I departed the caring arms of the mothership and decided to brave the world on my own. I have what is euphemistically called a portfolio career. A friend told me that’s what panicking about the mortgage and hovering over the emails, waiting for business, is called nowadays. I now call myself a forensic botanist, although that does not cover all that I do. I’m also a hired entertainer, a public speaker, aiming to enthuse people about the world of plants. Where I can, I also try to continue some of the botanical research that interests me.

  Usually, the first reaction when I introduce myself is ‘forensic what?’ Sometimes there might be a bit of tittering around the word ‘botany’ – the Carry On gene is never very far away in the British psyche. Many people have not heard of botany and if they have, they think it’s another word for gardening. Botany is not gardening, although gardening quite often relies upon knowledge originating from the research of botanists. In fact, botany is arguably the oldest scientific discipline. Humanity has been examining, describing and trying to understand plants and fungi since antiquity. Until the early sixteenth century, most European knowledge about plants was based upon the work of ancient Greeks such as Theophrastus and Dioscorides, and much of this knowledge was intertwined with medicine. From about 1550 the modern science of botany evolved rapidly, and now takes in all aspects of the life of plants, their morphology, anatomy, physiology, ecology, genetics, classification and evolution. Traditionally, botany also included the study of fungal organisms. Today, because of our increased understanding of the major biological differences between plants and fungi, the study of fungi is a separate discipline and is given its own name – mycology. These differences often surprise people, but what is even more surprising to many is that fungi are more closely related to us than they are to plants. Animals and fungi are opisthokonts. The word opisthokont refers to similarities in the cell structure and chemistry of both groups.

  I appreciate that some non-scientists often feel confused or daunted by scientific names, but they do get easier with a little perseverance. In many cases you’re using them without realising they’re scientific. Familiar garden plant names like geranium, eucalyptus, chrysanthemum and fuchsia are all scientific in origin. Similarly, every time you say octopus or hippopotamus, you’re using scientific names. In themselves, scientific names are not
important, they are gateways to information. I know this sounds counter-intuitive, especially from a scientist. But a name is essentially an aide-mémoire that accesses the important information that relates to the object in question. Thus, in the case of the common lawn daisy, its universally accepted scientific name, Bellis perennis, was first published by Carl Linnaeus in 1753. In itself, the scientific name is not a vital piece of information, but it leads us to all the published science that has been written about that plant over the last two and a half centuries. The use of a universal name for organisms reduces the potential for confusion. This name is called the binomial. A binomial is made up of two parts, the genus (Bellis) and the species (perennis). Essentially, the genus is the collective noun for a grouping of closely related species. In the case of Bellis, there are other daisy species, such as Bellis annua and Bellis sylvestris. To save space, botanists often abbreviate the genus name, in this case to, ‘B.’. To see B. annua and B. sylvestris growing wild you’ll have to go to southern Europe and the Mediterranean as they do not occur on these shores.

  A binomial allows a fellow scientist, or expert witness or jury, to have a high confidence that what I am discussing is comparable to their understanding, that it has verifiability. We humans apply the concept of naming (nomenclature) to many, many things in our world. The naming of elements and compounds in chemistry is a form of nomenclature. One of the objectives of this book is to give the reader an insight into the world of forensic botany, and the application of scientific names is part of that. In presenting my observations on a plant or a plant fragment I need to be able to convey what I think it is, as well as validate my conclusions, and this can only easily be done via the name.

  I could choose to use only the English vernacular name for the plants discussed. But, unfortunately, while many plants have a standard English name, some do not. More problematically, there is a great variation in which English names are used. A classic example is ‘bluebell’. In England this is traditionally applied to Hyacinthoides non-scripta and in Scotland, harebell, Campanula rotundifolia formerly bore the name. Some of our wild plants can have dozens of regional name variations. Cleavers (Galium aparine), is an annual plant that is common across our lowlands and it bears a host of now largely forgotten names – bobby buttons, catchweed, claggy meggies, gollen weed, goosegrass, herriff, sticky bob, robin-run-the-hedge and sticky willy are a small selection of those names. Generally, scientific names are much less prone to this level of variation.