Cat litter clue to catch arsonists
Cat litter could prove to be an invaluable tool for crime scene investigators (CSIs) trying to catch arsonists, a study has shown.
Traces of petrol on hard surfaces such as concrete can more easily be detected using the absorbent material than by any other substance, according to a study by forensic scientists at Anglia Ruskin University.
Most brands of cat litter contain the mineral sodium bentonite, which retains petrol on its surface.
CSIs often rely on sniffing petrol, or use sniffer dogs. But because they often do not get to survey a crime scene until some time after a fire has taken place, any petrol present could have evaporated or soaked into the floor.
Police across the country have experimented with a number of products to avoid having to dig up concrete floors to analyse in a lab.
These include sand, flour, powdered mashed potato, and sanitary towels.
But none has used cat litter, which has been found to be the best absorbent.
Another advantage of not digging up the floor is that small pieces of concrete and dust that could contain petrol are not accidentally deposited in other areas of the crime scene.
Petrol is a complex mixture of around 200 components and 15 need to be detected for the presence of petrol to be proven in court.
Garry White, a PhD student at Anglia Ruskin University, which has campuses in Cambridge and Chelmsford, Essex, said: "There are currently no reliable, or standard, products used by CSIs to sample petrol for later detection.
"However, our research has shown that cat litter is the best product available and, most importantly, fulfils the criteria laid down by UK courts."
Scientists will now attempt to adapt cat litter to improve its ability to detect other flammable materials, particularly diesel.
The aim is to develop a universal absorbent to aid detection of ignitable liquids and to contribute to a standard method that is used in fire investigation, and accepted by courts, across the world.