Exploring the influence of washing activities on the transfer and persistence of fibres in forensic science

In forensic science, a robust and sound interpretation and evaluation of transferred fibre evidence requires an understanding of the principles and mechanisms that underpin fibre transfer, yet existing research lacks consistency and repeatability. This study investigates the impact of washing activities on both the release of fibres into wastewater and the transfer of constituent fibres from donor garments to receiver swatches. Using a low-cost friction tester and automated data collection through photography and ImageJ image processing software, controlled conditions were maintained for repeated experiments. Results indicated significant fibre release during wash cycles, with load size and donor garment history playing crucial roles. The donor garments subjected to repetitive washes exhibit a progressive decrease in the number of fibres transferred, independently of the load size. This study underscores the importance of considering a garment's washing history in forensic science contexts, but also for consistency in the way that data are collected.