Mud or murder?

Abody has been found in woodland. A suspect denies having been to the site. There is little evidence apart from a tiny amount of the victim’s blood – or is there? Could a geological sleuth provide the answer from mud on the defendant’s shoe? The British Geological Survey (BGS) hopes so through its development of forensic geology techniques. Sir Arthur Conan Doyle introduced the idea of forensic geology in his first Sherlock Holmes story, A Study in Scarlet, in 1886: ‘Knowledge of Geology. – Practical, but limited. Tells at a glance different soils from each other. After walks has shown me splashes upon his trousers, and told me by their colour and consistence in what part of London he had received them.’ In forensic investigations, for example, where earth from a crime scene has stuck to a car’s wheel arch, a suspect’s clothes or shoes, the police may well ask where the particles came from.