The point of research
The focus had always been on the sharpness of the blade edge. No one had ever investigated the sharpness of the point. Until Professor Sarah Hainsworth took an interest...
Professor Hainsworth, who teaches in the Department of Engineering at the University of Leicester, is one of the world’s foremost forensic experts in her field: knives. And when it comes to criminal investigations involving sharp implements, her research has been pivotal.
When she embarked on an undergraduate research project on the sharpness of knives back in the 1990s, little did she know that the results of her work would end up in court. Her research has provided a fresh understanding of the different factors involved in assessing knife sharpness – which relates to the level of force used in knife crime.
Professor Hainsworth was approached in 2004 by a solicitor who asked her to test the sharpness of a knife used in a murder, to establish whether it could have easily inflicted the type of wound found on the victim. It was then that she realised there was a vital knowledge gap that she was ideally qualified to fill.
Working closely with Professor Guy Rutty of the University’s Forensic Pathology Unit, Professor Hainsworth employed high speed video to understand how knife points penetrate the skin and a drop testing rig to study the wounds made by various blades. In this way she has built a large database with a register of the sharpness and penetrability of a range of knives. Her work is increasingly being used within the criminal justice system - which just goes to show how our sharp minds are making a real difference.