Professor Patricia Wiltshire has helped police to solve countless major crimes. And it’s all down to a passion for plants. Amanda Riley-Jones meets Ashtead’s botanical sleuth...
It has been half a century since Professor Patricia Wiltshire began formally studying the world of plants. Little did she imagine, however, that her decision – born of an almost lifelong love affair with the natural world – would one day bring comfort to grieving families and cause ripples in the law courts of the land.
Professor Wiltshire is the UK’s leading forensic ecologist, whose expert analysis has been brought to bear upon more than 250 criminal cases, including some of the most high-profile of the past 25 years. Her memoirs came out in the spring.
Born in South Wales, she endured repeated chest infections as a child that often left her too ill to attend school, her education rescued by a set of encyclopedias from which she taught herself “everything from music to knitting and nature”.
When she was eight, however, Patricia’s parents sent her to stay with her grandmother in Rhyl, on the North Wales coast, hoping that the sea air would restore some life to her lungs.
“I adored being with my grandmother, Vera May,” says the self-effacing trailblazer in her gentle Welsh accent, speaking from the Ashtead home she shares with husband David Hawksworth, a world-renowned mycologist (fungi expert), and their little rescue cat, Maudie.
“She knew all about the natural world: which plants were edible and which were poisonous. She showed me the hedgerow plants and berries that provided a natural larder. For two wonderful years, she taught me all the things she knew.”
Great was the joy of poking around the lawn with scissors.
“I found so many tiny, obscure foreign things between the chopped-off grass. I realised that the soil was infinitely variable over short distances and home to so many little things with legs. This is where it all comes from – this fascination, not only with nature but with the stuff beneath the surface.”
After gaining a first in Botany and Ecology at King’s College London, Patricia went on to lecture there, before moving up the road to University College (UCL). There she was engaged in palynological – the study of pollen, plant spores, fungal spores and any microscopic entity in a sample – research.
“I analysed sediments from archaeological sites, providing evidence of past landscapes and the land-use of prehistoric people,” she explains.
Dash to the north from Surrey for a murder
And it was while she was happily reconstructing the past that a call came from Hertfordshire Police and changed the whole course of her life.
The force was investigating a Triad gang murder, explained the detective. They had a body, a car and some suspects. What they didn’t have was proof that the car had been used to drive the victim through the field where his burned body had been found. The senior investigator wondered whether pollen from the field’s crop could be found on the car. Kew Gardens didn’t know – but they knew a woman who might.
“I never imagined that I would be presented with anything like this,” recalls Patricia. “I said: ‘I can try, but I have to warn you that I might not find anything.’”
In fact, Professor Wiltshire was key in helping the police to secure a conviction. The car contained palynological evidence that the occupants had stepped in vegetation at the edge of an arable field and adjacent to an ancient hedge. When detectives showed her the field, she was able to pinpoint the spot where the body had been found.
“I had seen it in my mind’s eye: the blackthorn and the field maple, their canopies intertwining. Grasses, white dead-nettle, black nightshade, woundwort, docks, goosefoot. There was simply no other place along that hedge it could have been.”
On another occasion, Patricia helped police to find the missing body of a young woman who had been murdered by her fiancé.
“When I saw the pollen and spores on the slides made from his Reebok trainers, the foot pedals and the car mats, and then the birch pollen all over the tines of a garden fork, the place leapt out at me.
“I told the police: ‘You will need to go along an open track and eventually there will be a stand of mature birch trees. You will find Joanne in a hollow, off the path, and she will be covered over with birch twig litter.’ I received a letter from Joanne’s parents thanking me for bringing their girl home, which brought a rush of emotion.”
Then there was the rape victim spared the agony of the witness box after Patricia demonstrated that pollen and spores profile from leaves and soils at the crime scene were overwhelmingly similar to that on the boy’s clothes.
“The boy must have been stunned that his jacket had revealed the truth about his attack, and he reluctantly confessed.”
And the 77-year-old professor, who created and taught a Masters course at UCL in Forensic Archaeological Science, has no plans to retire.
“Hard work keeps your brain active! I am still happy to accept cases if they are sufficiently interesting. I’ve done three this year.”
Now her first book is out.
“Publishers had been begging me to write one for years,” she says. “I had so much material in my head, it only took nine weeks!”
And the dedication? It is to the grandmother who inspired her lifelong passion for plants. Naturally.
Here's how she does it:
By profiling the pollen and spores and other microscopic entities on the clothing of a suspect or victim, the car in which they travelled or the tools used, or even the insides of the corpse, it’s possible to conjure up an image of the kind of places they have contacted and, sometimes, what has happened to them,” explains Patricia.
“I have developed the protocols by which the discipline of forensic ecology is now defined, but no two situations are the same. Often I have had to invent ways of retrieving microscopic evidence from objects and materials while at the crime scene, or in the mortuary.”
In the body-in-the-car case (see the main story), Professor Wiltshire retrieved evidence from the car by meticulously cleaning different areas to sieve and decant the silty washings and centrifuge them down to concentrated pellets. She then treated the pellets with strong acids to remove the background matrix of the soil, thereby revealing the pollen, spores and other microscopic material.
At this point, pollen grains and fungal spores are stained red, embedded in jelly and spread onto slides.
“I scan sample after sample, counting and identifying the mixture of palynomorphs,” says Patricia.
Once she’s identified all the species, she starts to visualise their typical habitat: the acidity and wetness of the soil, well-lit or shady, the type of woodland and so on.
“It might take hours, weeks or longer,” she says. “Barristers know little of plant science or ecology. I was once challenged with: ‘Dandelions are found everywhere, aren’t they?’ Well, of course, they are not.
“Nothing must be left to chance if one is to give a robust performance in court, but no palynological analysis offers absolute proof of contact. It’s all about likelihood. Time and again though, I’ve seen a tiny hint from nature help to point us in the right direction so that justice can be served.
Traces: the memoir of a leading forensic scientist and criminal investigator, by Patricia Wiltshire, published by Blink Publishing (£20)
