Forensic analysis of an alleged improvised explosive device (IED) from a multidisciplinary perspective: Organisation and outcomes of the ENFSI 2023 exercise.

Interdisciplinary examination of test materials requires careful consideration of how forensic routines can influence each other. This influence can be direct and obvious, or indirect and subtle. A multidisciplinary collaborative exercise (MdCE) should test a forensic laboratory's ability to account for these difficulties. Therefore, the MdCE should be set up in a way that considers how the applied procedure (i.e., the sequence of forensic disciplines) can impact the outcomes (i.e., the ability to recover traces). Building on lessons learned from a previous experience, this article summarises the concepts, planning, design, preparation, implementation, coordination and evaluation of the ENFSI 2023 Multidisciplinary Collaborative Exercise (2023-MdCE) covering a range of forensic disciplines, specifically DNA, fingerprints, explosives, fibres, and hair morphological analysis. The exercise consisted of a glass jar with black adhesive tape around it, representing an improvised explosive device. The analysis of the results highlighted: a) the importance of a joint preliminary optical examination; b) some critical issues regarding the explosives/fingerprint sampling strategies; c) the potential impact of contact marks that may contain friction ridge detail on items that were different from those deposited by the organiser; d) the importance of avoiding discrepancies in labelling exhibits and/or traces is emphasised as it is related to the communication strategy of scientific forensic results. Additionally, recommendations and suggestions are provided for those who may wish to undertake such a collaborative exercise.