Dear Readers, this talk featured murder, corpses and crime scenes. It wasn’t overly gruesome, but if you’re feeling a bit down you might want to move on….

Dear Readers, I always wondered if I could be a forensic entomologist – someone who uses insects and their remains as a way of gathering evidence about crime – but I’d never thought about the role of the forensic botanist until I signed up for a talk that  Dr Mark Spencer gave for Plantlife last week. And what a fascinating field (pun intended) it is!

Forensic botany has a much longer history than I realised – in fact it played a pivotal role in the case of the kidnapping of Charles Lindbergh Jr back in 1932. This case stunned the USA at the time – the young child of the aviator Charles Lindbergh was taken from an upstairs window and held for a ransom, which was paid but the child was found dead in woodland a few weeks later. The case centred around the ladder that was used to gain access to the window – it was found to be composed of both recycled and new wood. The forensic botanist, Dr Arthur Koehler, discovered that the new wood came from a variety of pine that grew only in the eastern USA, so he contacted the 1200 woodmills in the area, and asked them all to send him a sample. From this, he was able to narrow the wood down to only two woodmills, and from one of them he retrieved the receipt from the man who was eventually executed for the murder, Richard Hauptmann. When the police went to Hauptmann’s house, Koehler was able to match the recycled wood in the ladder to missing beams from the attic. All in all, the evidence was damning (especially as a suitcase containing $14,000 of the ransom money was also found in Hauptmann’s house), but questions were raised about witness tampering and planting of evidence, and also about whether Hauptmann acted alone.

In the present day, Dr Spencer is often called in missing person cases, or where the circumstances around a discovered dead person needs to be investigated. He explained that the vast majority of crimes occur in private houses or in ‘non-natural’ places, such as streets, car parks or other urban areas, and that the police, like the rest of us, often suffer from plant-blindness, a kind of tendency to see everything through the lens of being human. He has been able to look at a crime scene that the police were preparing to clear, full of brambles and other undergrowth, and to tell them not to bother, because the plants were all older than the crime and there was no sign of disturbance. Similarly, along with forensic archaeologists, he’s been able to say that a body was definitely not buried in a particular site because there had been no mixing of the upper and lower strata of the soil.

He was also able to debunk the myth that plants, especially nettles, will grow especially vigorously where a body is buried – in fact, a human body is largely toxic to plants in the first few years of decomposition. However, he did point out that brambles and ivy will both eventually grow over a body, ‘locking it in place’ in the landscape. Someone skilled in ageing the different shoots of bramble, such as Dr Spencer, can then give an estimate of how long the body has been in situ.

One of the saddest cases was that of ‘Adam’, a child from West Africa whose torso was found in the River Thames close to the Globe Theatre back in 2001. He was never identified, and the rest of his body was never found, but isotope analysis showed that he had only been in the UK for a matter of days. He was wearing a pair of orange shorts, a colour that was often used for votive offerings. The suspicion was that the child was used for a practice known as muti – the child’s body parts would be used for potions to cure illness, ensure success etc. The forensic botany investigation revealed that the child had been poisoned with Datura (Thorn Apple) and Calabar/Ordeal Bean, which is found only in West Africa. Dr Spencer described this as one of the most distressing cases in which forensic botany had played a part.

All in all, this was a compelling talk – Dr Spencer talked about what an honour it was to work with the police and other expert witnesses, but most of all what an honour it was to work with the dead, and be able to tell their stories after they could no longer speak. The talk itself is only available to members of Plantlife, so sign up if you haven’t already! Their next talk is about children and their relationship with nature, which sounds like a complete change from crime scenes and corpses,  but I’m sure it will be no  less interesting. I shall report back!