"Evaluation of the presence of artifacts in the forensic biological examination
E. D’Orio1, K. Czerwińska1, C. Lucanto1 and G. Calabrese1
1Bio Forensics Research Center – Italy


Forensic biology examination is a part of forensic science which has the aims of identify biological stains on findings. Forensic biological examination is important for the identification of even the smallest biological stains and for prevent the contaminations phenomena during the forensic analysis. Previous studies shown that only 15% of the biological stains are easily identificable on the findings. In order to improve the efficiency of stain-identification, forensic operators use different technologies, such as alternative light sources (ALS). The ALS are forensic light, non-laser, designed with a white light source and equipped with a range of filters that allow to select the emitted radiation; the biological evidence, due to their characteristics, can react to this different wavelength light with absorbance signal or fluorescence signal. The results of these technical analysis could be affected by the presence of artifacts; in the area of forensic biology examination, artifacts are not well defined and described yet. In forensic genetics it is well documented the presence of different types of artifacts, such as drop in, drop out, spike, dye bob etc., which can lead to changes in results, making them not representative of the true biological material, or their presence makes much more difficult the interpretation of the forensic genetics results. Whereas, in forensic biology examination, the artifacts are different signal phenomena of absorbance and fluorescence not assigned to biological stains, but caused by the fabric’s composition. Through this study, it has been possible to identify two different types of artifacts. The first one, identified in this study as a letter “A”, is a fluorescence signal, normally of small size and brightly colored, that has been named“Brightling”. The second type of artifact, identified as “B”, can be observed as a dark and absorbance signal of larger size, has been called ""Shadowling"". The aim of this study was to define and describe for the first time the presence of artifacts in the forensic biological examination analysis. In the scientific literature, this topic is not explored yet and there is the necessity to highlight these phenomena to prevent false positives occurring in forensic biological examination. The study was performed in order to identify the presence of artifacts, discriminate between different types of artifacts, and understand how big can be their impact in the forensic biological examination."