title: Fibre persistence on immersed garment - Influence of water flow and stay in running water.
abstract: The persistence of fibre traces is a critical factor in the evaluation of fibre findings in forensic casework. Water can play a major role in affecting fibre persistence as a lot of fibre traces can get lost after washing incriminated garments, after rainfall over the victim's body or after immersion of the victim in water. The influence of immersion in standing water on fibre persistence was previously studied in our laboratory on various knitted recipient fabrics. The present study is focused on the persistence of target fibres on immersed cotton T-shirts through an immersion/stay/emersion process in running water (from 1h up to 7h), simulated in laboratory (~0.4l/s, gentle water flow conditions) and in real conditions (~2000l/s, medium water flow conditions). A gentle water flow slightly affects fibre persistence, which remains more or less constant over time, regardless of the duration of the stay in water. No rapid loss is observed during immersion in real conditions, including a medium water flow and boat activity. The fibre persistence in running water seems to depend mainly on the immersion step and also, in case of a medium water flow, on the stay in water with a linear loss over hours.
authors.affiliation: National Institute for Criminalistics and Criminology, Fibres and Textiles Laboratory, Chaussée de Vilvorde 100, B-1120 Brussels, Belgium. Electronic address: Laurent.Lepot@just.fgov.be.
authors.forename: L
authors.initials: L
authors.lastname: Lepot
authors.affiliation: National Institute for Criminalistics and Criminology, Fibres and Textiles Laboratory, Chaussée de Vilvorde 100, B-1120 Brussels, Belgium.
authors.forename: T
authors.initials: T
authors.lastname: Vanden Driessche
keywords: Activity; Forensic fibre investigation; Retention; Underwater conditions; Waterway