How soil on boots helped trace a killer to a crime scene

"Geological, chemical and biological characteristics can provide vital clues about where and how crimes have been committed or where and how death might have occurred, helping to contribute to the investigative jigsaw of crime investigation"

The critical role soil can play in forensic investigations has again been highlighted by the involvement of the James Hutton Institute's soil forensics team in a high-profile case, this time the inquiry by Police Scotland into the disappearance and murder of Emma Faulds, whose remains were found in Glentrool Forest, Dumfries and Galloway, in June 2019.

As part of the forensic inquiry, microscopic traces of soil recovered from the boots of the accused, Ross Willox, were an important part in narrowing down the search area and establishing a link to the place where Emma's body was found.

Professor Lorna Dawson, head of Soil Forensics at the Institute, explained: "One of the police officers in the search team knew the topography well and suggested areas to prioritise from the description of the soil and vegetation that I recovered from Ross Willox's boots.

"It was clearly peat on a boggy upland area. The composition of the mosses on the accused's boots was consistent with those seen at the area where Emma was found. Seven of the 12 plant species observed to be at the area where Emma was found were recovered from Willox's boots. Our botanist at the Institute identified the species of moss found on the boots using high-power microscopy."

The organic analysis of the soil samples recovered from the accused's boots was instrumental in linking them to the scene and contributed to his conviction after a six-week trial.

In an official statement from Police Scotland, Detective Inspector Peter Crombie, the lead investigator on the inquiry, said: "Ross Willox was a friend of Emma's and had known her for a number of years. What happened between him and Emma at his home that night remains unclear, and only he truly knows what led to her death.

"Willox's actions with regard to the disposing of Emma's body are incomprehensible and sickening. Her family could have been denied being able to mourn their loved one with a funeral or knowing her final resting place. Thankfully, due to the efforts of officers, we were able to find Emma which allowed her family some comfort."  

Professor Dawson commented: "In addition to being an essential resource for food security and human sustainability, soils contain many physical, chemical and biological characteristics, along with trace material, such as plant debris and physical particulates, which can potentially be of great use to the investigative and reconstructive processes.

"This information can assist the intelligence stage of an investigation, such as the search of a missing person, and provide trace evidence which could be subsequently presented in court, both being of use in this particular case."

Professor Dawson has taken part in many high-profile forensic inquiries and has presented evidence in many cases including those of  convicted murderers Angus Sinclair and Christopher Halliwell.

"Geological, chemical and biological characteristics can provide vital clues about where and how crimes have been committed or where and how death might have occurred, helping to contribute to the investigative jigsaw of crime investigation," Professor Dawson concluded.