Abertay University develops method to take fingerprints from food
Forensic scientists at the University of Abertay in Dundee have become the first in the UK to recover latent fingerprints from foods.
Only two other studies have ever reported recovering fingerprints from foods, but the research was carried out in India and Slovenia.
Those studies both used chemical substances that are not routinely used in the UK.
The technique could prove useful to police forces and the justice system.
Recovering fingerprints from foodstuffs has proved problematic in the past and as such, it is often overlooked as evidence.
However, by modifying an existing technique that was initially designed to recover fingerprints from the sticky side of adhesive tape, the team at Abertay said this need no longer be the case.
Dennis Gentles, a former crime scene examiner and forensic scientist who has worked at Abertay University for the past 10 years, said: "Although there are proven techniques to recover fingerprints from many different surfaces these days, there are some surfaces that remain elusive, such as feathers, human skin, and animal skin.
"Foods such as fruits and vegetables used to be in that category, because their surfaces vary so much - not just in their colour and texture, but in their porosity as well.
"These factors made recovering fingerprints problematic because some techniques, for example, work on porous surfaces while others only work on non-porous surfaces."
He added: "The fact that we've managed to successfully recover prints from such difficult surfaces as foods is another step forward in the fight against crime.
"It may not seem like much, but a piece of fruit might just be the only surface that has been handled in a crime scene so developing a trusted and tested technique to recover fingerprints from such surfaces is something to be valued by crime scene examiners."
The two previous studies, carried out in India and Slovenia, involved chemicals which are not used in the UK.
Instead, the team modified a substance known as Powder Suspension, a thick, tar-like material, and found that it produced a clear, high-quality mark on the smooth-surfaced food items such as onions, apples and tomatoes.
Mr Gentles said: "Although Powder Suspension was initially developed to recover prints from the sticky side of adhesive tape, it's since been found to work on other surfaces, so we wondered whether it would work on foods, as this was something it hadn't been tested on before.
"We found that it out-performed all the other methods we tested.
"Although there's still a considerable amount of research to do before we can recommend techniques for all types of foods, we've shown for the first time that it really is possible to recover fingerprints from them, something that was previously thought to be unachievable."
The publication of the team's research, in the forensic science journal "Science & Justice" means that others will now be able to replicate their results.