Professor David Foran describes in a recent online MUNCHIES article how police can use food left at the scene of a crime to aid in determining possible suspects. How Cops Use Pizza Crusts and Half-Eaten Burgers to Solve Murder Mysteries outlines two cases in which examining the DNA left on discarded food steered police toward arrests.
Professor Foran states that while police have “been collecting cigarette butts for a long time … the idea that a piece of food might be evidence, or a piece of gum on the ground, is subtle. They are probably more aware of that now and are more willing to collect it.”
As technology has progressed, less DNA has become needed for definitive testing. Foran states that in the past, “the rule of thumb was that you needed a bloodstain about the size of a nickel to do DNA testing. Nowadays, you can do it on stuff you can’t even see.”
David R. Foran is the Director of the Forensic Science Program at Michigan State University, housed within the School of Criminal Justice. His area of expertise is forensic biology, with an emphasis on nuclear and mitochondrial DNA analysis of humans, and domestic and wildlife species.