School of Pharmacy & Biomolecular Sciences, Liverpool John Moores University, Byrom St, Liverpool L3 3AF, United Kingdom.
School of Biological & Environmental Sciences, Liverpool John Moores University, Byrom St, Liverpool L3 3AF, United Kingdom.
Sci Justice. 2023 May;63(3):376-386. doi: 10.1016/j.scijus.2023.03.004. Epub 2023 Mar 31.
Environmental trace evidence offers useful circumstantial intelligence to link persons and scenes of forensic interest. An increasing empirical research base is dedicated towards understanding the transfer and persistence dynamics of environmental indicators including pollen, soils, and diatoms, within a diverse range of experimental frameworks. This paper presents two discrete studies exploring transfer and persistence of soils and sediments on footwear and diatomaceous earth adhered to clothing in forensically pertinent scenarios. Variables including sediment type, foot position, clothing type, and body positioning were also explored throughout. Both experiments incorporated a field-based methodology during the sampling effort. Photographs were collected of an initial transfer sample and of a retained assemblage following hours, days, and up to one-week of wear, facilitating macroscopic assessment of trace evidence dynamics. All images were processed using accessible, open-source software before spatial analysis of evidence distribution within and temporal assessment (% retention) upon each evidential surface. The results highlighted consistent loss of transferred sediment from footwear with significantly greater retention of loamy clay soil than dune sand which was absent beyond 24 h of wear. Loss was not influenced by wearer gait but was more rapid from those areas of the shoe sole in direct contact with the ground. Diatomaceous earth was retrieved from all three clothing types tested after one week - significant losses of material occurred before 48 h with a consistent assemblage identified beyond this. Denim was significantly more effective than acrylic and fleece for diatomaceous earth retention and significantly more material was lost from clothing worn on the lower body. These findings highlight the value of using visual environmental markers and a macroscopic analytical approach during the investigation of environmental trace dynamics. The methodology offers a novel, non-destructive assessment of soil and diatom transfer and persistence, complementing more extensive laboratory-based examinations to ensure the development of a well-rounded research base within the forensic sciences.
环境痕迹证据为将人与有 forensic 兴趣的现场联系起来提供了有用的间接证据。越来越多的经验研究致力于理解环境指标（包括花粉、土壤和硅藻）的转移和持久性动态，这些环境指标在各种实验框架内。本文介绍了两项离散研究，探索了在 forensic 相关场景中，鞋类和附着在衣物上的硅藻土上的土壤和沉积物的转移和持久性。研究还探索了包括沉积物类型、脚部位置、衣物类型和身体位置在内的变量。两个实验在采样过程中都采用了基于现场的方法。对初始转移样本和经过数小时、数天甚至一周的穿着后保留的组合进行了拍照，方便对痕迹证据动态进行宏观评估。所有图像均使用可访问的开源软件进行处理，然后对证据分布进行空间分析，并对每个证据表面的保留百分比进行时间评估。结果突出显示，从鞋类上转移的沉积物持续一致地丢失，而粘性粘壤土的保留率明显高于沙丘砂，在穿着超过 24 小时后就不再存在。磨损者的步态不会影响损失，但从鞋底与地面直接接触的区域损失更快。经过一周的时间，从所有三种测试的衣物上都提取到了硅藻土——在 48 小时之前发生了大量材料损失，超过这个时间后就确定了一致的组合。与丙烯酸和羊毛相比，牛仔布在保留硅藻土方面更有效，而且从穿在下半身的衣物上损失的材料更多。这些发现强调了在调查环境痕迹动态时使用视觉环境标记和宏观分析方法的价值。该方法提供了一种新颖的、非破坏性的土壤和硅藻转移和持久性评估方法，补充了更广泛的实验室检查，以确保在 forensic 科学领域内建立一个全面的研究基础。
