Can “contamination” occur in body bags?—The example of background fibres in body bags used in Australia

© 2016 Elsevier Ireland Ltd Impurities that are transferred to a crime scene or a body can have a significant negative impact on the investigation if the existence of the contamination is not known, and the source of the contamination is not identified. Forensic consumables, such as DNA swabs, have been known to have caused contaminations, wrongfully linking crimes throughout Europe. In that context, this study focused on body bags, widely used to transfer a corpse from the crime scene to the morgue. Our preliminary survey showed that several countries and Australian Jurisdictions are conducting the sampling of trace evidence at the morgue after the transportation of the body. Potential impurities present in body bags could thus interfere with pertinent traces. The aim of this work was to qualify and quantify the background contamination of trace evidence in body bags used within Australia. Fifteen body bags from four Australian Jurisdictions or laboratories were searched for micro traces. Impurities such as fibres and unidentified particles were detected in each examined body bag, with an estimated average of 3603 coloured fibres and 1429 unidentified particles. This number of fibres is similar to the amount found on a vinyl cinema seat in other studies. Various other contaminants such as pieces of fabric, hairs, parts of insects or feathers were also observed. It is hypothesised that these impurities are introduced during the manufacturing process. This high number of impurities can lead to incorrect conclusions and misleading investigative leads. This paper presents an overview of the problems these impurities can cause and proposes several strategies to prevent future issues

The transfer and persistence of petrol on car carpets

The significance of the presence of petrol in motor vehicle fires has often been challenged due to the possibility of a natural occurrence of petrol residues inside the vehicle. Transfer and persistence studies were undertaken to investigate the potential transfer and persistence of petrol onto vehicle carpets through the 'normal' usage of motor vehicles. The results of the transfer study indicate that petrol may be transferred from the external environment in sufficient quantities via the shoes of drivers or passengers to be detected after a 24 h period, but not after 1 week. Low levels of petrol were detectable after 24 h on all carpet mats where the initial volume was 500 μL or more. The level of evaporation of the petrol detected increased with corresponding increases in the time period between transfer and analysis. The results of the persistence study indicate that small volumes of petrol (less than 100 μL) are unlikely to be detected on carpet after a 24 h period, and volumes of less than 1000 μL are unlikely to be detected on acoustic padding after this time period. Larger volumes may be detected after this period, but will generally not be detectable on either carpet or acoustic padding after 4 weeks. In each case, the petrol that is detected exhibits a chromatographic profile of greater than 60% evaporated petrol. These results demonstrate the significance of finding a large volume of fresh or slightly evaporated petrol on car carpet. © 2004 Elsevier Ireland Ltd. All rights reserved

A survey of glass found on the headwear and head hair of a random population vs. people working with glass

This study investigated the prevalence of glass particles on the headwear and head hair of two different population groups; the general public who do not work with glass, and glaziers from O'Brien® Glass Industries who work with glass and have regular contact with broken glass. The 232 samples collected from the head hair and headwear from the random population resulted in the recovery of 6 glass fragments in total on 6 individuals (i.e. one fragment each). All of these fragments were from head hair samples with no multiple fragments recovered. The two headwear samples that were taken revealed no fragments. These results were in contrast to the survey that was conducted on the head hair and headwear of 25 glaziers from O'Brien®, in which 138 glass fragments were found in total on 24 of the 25 glaziers. The size and number of fragments found in each sample were also generally larger for the glaziers group. The results from this study indicate that the prevalence of glass on the head hair and head wear of the random population is very low in comparison to the head hair and headwear of those who have regular contact with breaking glass. The significance of this finding with respect to the interpretation of glass evidence is also discussed. © 2013