Evaluation of the use of chemical pads to mimic latent fingermarks for research purposes Romain Steiner*, Sebastien Moret, Claude Roux University of Technology Sydney, Centre for Forensic Science, PO Box 123, Broadway, NSW 2007, Australia A R T I C L E I N F O Article history: Received 15 May 2020 Received in revised form 26 June 2020 Accepted 8 July 2020 Available online 13 July 2020 Keywords: Artificial secretion detection Simulant IFRG guidelines quality control Technique A B S T R A C T Fingermark detection is in constant evolution, with new techniques being developed and existing ones being continuously optimised. Recently, researchers have begun to express interest in artificial fingermark secretions to overcome the issues arising from the variability of fingermark composition. Some of these artificial secretions have started to appear on the market in the form of pads that can be used to deposit fingermarks with a known and controlled composition. This study aimed at assessing the reliability of three commercially-available pads by comparing the results to those obtained by real fingermarks, using six detection techniques (1,2-indanedione/zinc, ninhydrin, cyanoacrylate followed by rhodamine 6G staining, gold/zinc vacuum metal deposition, and physical developer) on five substrate types (copy and recycled paper, acetate, glass, and glossy paper). The results showed that the artificial fingermarks deposited with these pads reacted in an unreliable way, notably when treated with complex detection techniques such as Physical Developer. Further, the high concentration of some of the target compounds found in the artificial secretion led to an over performance of some detection techniques, which could mislead the operator to overestimating the efficiency of a given method. The resulting artificial fingermarks are considered too dissimilar to real fingermarks to be used as quality control standards and better simulants need to be found for a more efficient and realistic control of the variability. © 2020 Elsevier B.V. All rights reserved. 1. Introduction There is an ongoing effort in fingermark detection research to develop more efficient detection techniques or improving existing ones. With the extended number of research groups around the world, the need to develop a standardised research framework has been acknowledged [1,2]. This led to the publication of guidelines by the International Fingerprint Research Group (IFRG) for the assessment of fingermark detection techniques [3]. The main idea behind these guidelines was to strengthen research methodologies and hence reinforce the value of the obtained results, including for inter-laboratory comparisons. The guidelines also distinguished four distinct phases in the development of a fingermark detection technique: pilot studies, optimisation and comparison, validation, and operational evaluation (or casework trials). The required number of donors and fingermarks for each of these phases can vary from 3 to over 20 depending on the research phase. The IFRG guidelines are a valuable aid for researchers developing detection methods but they are not full proof as they cannot guarantee that the efficiency of a given fingermark detection is not influenced by some other undetermined factors. Going through all four phases described in the IFRG guidelines can be very labour-intensive and, in some cases, coordinating all the donors can be problematic, especially when their presence is required on a particular day (e.g. when fingermarks have to be aged appropriately). In addition to this logistical problem, the quality of the fingermarks deposited by the donors is influenced by many parameters that cannot be fully controlled by the operator. In those cases, the use of artificial secretions with a known and fixed composition instead of real fingermarks could be desirable and justified. Beside the clear advantage artificial secretions can have by making the whole process less laborious and removing the influence of donors from the variables, their known and controllable composition also allows for inter-laboratories comparisons. One critical characteristic of latent fingermarks is at the centre of this issue: their variability in composition. Clear instructions about the deposition method, such as the type of fingermark wanted and the pressure they must apply on the substrate are often given to the donors, but those precautions cannot guarantee a full control of the composition of fingermarks left by an individual. * Corresponding author. E-mail address: Romain.Steiner@uts.edu.au (R. Steiner). http://dx.doi.org/10.1016/j.forsciint.2020.110411 0379-0738/© 2020 Elsevier B.V. All rights reserved. Forensic Science International 314 (2020) 110411 Contents lists available at ScienceDirect Forensic Science International journal homepage: www.elsevier.com/locat e/f orsciint