Where did they come from? The accumulation of fibres from the home environment on daily wear

Abstract

Forensic fibre comparisons are not limited to the fibres from garments purported to have been worn during or involved in the incident. They extend to potential secondarily or higher order transferred fibres originating from textiles in frequented environments. Comparisons in these cases may be made to recovered known textiles, or to other fibre collectives found in the environment and clothing of the involved individuals. The results of such comparisons have been purported to be valuable due to several assumed axioms. First, that the fibre population of an environment is highly characteristic. Second, that these fibres reliably accumulate onto everyday wear from day-to-day activities in these environments. Finally, that these fibres accumulate in significant enough quantities to form a pool of fibres that can be transferred again in meaningful quantities. This study addresses these assumptions by studying the accumulation of fibres from home environments on daily wear. 24 participants were recruited to submit clothing worn in their home. These clothes were taped and examined with microscopy to evaluate the diversity of fibre populations of different homes. Following this, 5 of these 24 participants participated in a longitudinal study where target fibres were identified from their first submission. Potential origins of these target fibres were searched for in their homes and compared with fibres recovered from the submitted clothing. Undifferentiated known materials were then used to access the intra-variability of the target fibres. Meanwhile these 5 participants continued to submit clothing of their own along with clothing provided to them over the course of 5 – 6 months. These were also taped and examined with microscopy to assess the quantity of these target fibres. The results provided support for the three mentioned assumptions, which strengthens the case for carrying out such comparisons in practice. Furthermore, the data could be reliably modelled with a negative binomial linear regression based on factors such as shedding, use, and storage. Such models allow for more robust evaluation of scientific findings in fibre comparison cases of related nature.