Approximately 1,000 to 44,000 fibres could get cross-transferred between the garments of a victim and their assaulter in a physical assault scenario, a study finding that the researchers involved believe could inform the evaluation of fibre evidence in such cases.
The number could vary with noticeable differences between different assault scenarios, the study from Northumbria University and King's College London, UK, said.
In the interpretation of forensic evidence in many criminal cases, knowledge of the number of fibres transferred during a physical activity is essential.
Previous studies have provided important data on how variables such as increased time and pressure during physical contact can impact the number of fibres which transfer. However, the extent and variability of fibre transfer in uncontrolled scenarios including real-life situations, is largely unknown.
Kelly Sheridan, Assistant Professor of Forensic Science in Northumbria University's Department of Applied Sciences, believes the findings will help fill a knowledge gap in the forensic field.
"We wanted to investigate the extent of fibre transfer during different types of physical assaults using real people for the first time," said Sheridan.
Their work is published in the journal Science & Justice.
The fibre transfer occurring between garments during physical assaults was assessed in this study by simulating the act with people from Northumbria's Jiu Jitsu club.
The members of the club were asked to enact the role of an aggressor or a victim in four simulated scenarios which included high and low intensity activities over different time periods.
"Primarily, what this has demonstrated is that the sheer quantity of fibres found to transfer are far greater than anything previously published," said Sheridan.
"Our style of Jiu Jitsu covers striking, throwing and to a lesser extent ground-fighting. We focus on a self-defence approach, so the situations Sheridan wanted to simulate were quite straight forward and familiar for us," David Chalton, Northumbria's Lead Coach for Jiu Jitsu, explained.
"The methodology we employed in this study provides a more robust assessment of the effects caused by actual physical assault scenarios, than any existing similar study available to forensic practitioners," said Ray Palmer, an independent forensic science consultant who is also an Associate Lecturer at Northumbria and worked with Sheridan to develop the research concept.
