The transfer of fibres between garments in a choreographed assault scenario

Our fundamental understanding of fibre transfer remains based on early seminal transfer studies that were largely mechanical simulations. However, transfer events in the real world are uncontrolled in nature. This study takes a novel approach to address this discrepancy, with skilled jiu-jitsu practitioners performing a choreographed 'standard' assault scenario to investigate the transfer of fibres between a cotton T-shirt and cotton/polyester hoody. Garments were collected immediately after the scenario and examined for the number, length and zonal distribution of transferred fibres. It was observed that cotton transferred the most fibres, on average twice as many from blended hoodies than T-shirts; whilst polyester transferred the least. Shorter fibres transferred and were recovered more readily than longer fibres; however, it was more likely to recover polyester fibres> 5 mm. The number and length of fibres transferred from the attacker's garment mainly depended on the construction of the donor textile (including sheddability) and properties of the fibres. Conversely, properties of the recipient textile were more significant factors when considering transfer from the victim's garment. Location of recovered fibres was found to be dependent on the wearer's role, but generally, upper zones and sleeves of both garments were most populated. Overall, these results will contribute to grow our current knowledge base regarding fibre transfer between donor and recipient textiles in a common assault situation. This will ultimately aid experts support evaluation with regards to competing hypotheses such as in a Bayesian framework.