Processed food eaters leave better fingerprints

The inventor of a new forensic fingerprinting technique claims criminals who eat processed foods are more likely to be discovered by police through their fingerprint sweat corroding metal.

Dr John Bond, a researcher at the University of Leicester and scientific support officer at Northamptonshire Police, said processed food fans are more likely to leave telltale signs at a crime scene.

Speaking before a conference on forensic science at the University of Leicester, Dr Bond said sweaty fingerprint marks made more of a corrosive impression on metal if they had a high salt content.

And he revealed he was currently in early talks with colleagues at the University of Leicester to assess whether a sweat mark left at a crime scene could be analysed to reveal a ‘sweat profile’, ie, more about the type of person who left the mark.

Dr Bond, from the Northamptonshire Police Scientific Support Unit, is an Honorary Research Fellow at the University of Leicester’s Forensic Research Centre. He has developed a method that enables scientists to ‘visualise fingerprints’ even after the print itself has been removed. He and colleagues conducted a study into the way fingerprints can corrode metal surfaces. The technique can enhance — after firing — a fingerprint that has been deposited on a small-calibre metal cartridge case before it is fired.

Dr Bond said: “On the basis that processed foods tend to be high in salt as a preservative, the body needs to excrete excess salt, which comes out as sweat through the pores in our fingers.

“So the sweaty fingerprint impression you leave when you touch a surface will be high in salt if you eat a lot of processed foods — the higher the salt, the better the corrosion of the metal.”

Dr Bond added there was, therefore, an indirect link between obesity and the chances of being caught of a crime. “Other research has drawn links between processed foods and obesity and we know that consumers of processed foods will leave better fingerprints,” he said.