Webb Julia C, Brown Harriet A, Toms Hannah, Goodenough Anne E
School of Natural and Social Sciences, University of Gloucestershire, Francis Close Hall, Cheltenham GL50 4AZ, UK.
School of Natural and Social Sciences, University of Gloucestershire, Francis Close Hall, Cheltenham GL50 4AZ, UK.
Forensic Sci Int. 2018 Jul;288:36-45. doi: 10.1016/j.forsciint.2018.04.010. Epub 2018 Apr 15.
Forensic palynology has been important in criminal investigation since the 1950s and often provides evidence that is vital in identifying suspects and securing convictions. However, for such evidence to be used appropriately, it is necessary to understand the factors affecting taphonomic variability (i.e. the variability in the fate of pollen grains before they are found during forensic examination). Here, we test the relative amount of pollen retained on clothing after a period of simulated light or heavy wear based on pollen and fabric characteristics. We also test the efficiency of forensic laboratory protocols for retrieving pollen from fabrics for analysis. There was no statistically significant difference in retention of fresh or dried pollen on any fabric type. There was a substantial difference in pollen retention according to wear intensity, with considerably more pollen being retained after light wear than after heavy wear. Pollen from insect-pollinated species was retained at higher concentrations than pollen from wind-pollinated species. This pattern was consistent regardless of wear intensity but pollination type explained more of the variability in pollen retention after light wear. Fabric type was significantly related to pollen retention, but interacted strongly with plant species such that patterns were both complex and highly species-specific. The efficiency of removing pollen with the standard washing protocol differed substantially according to plant species, fabric type, and the interaction between these factors. The average efficiency was 67.7% but this ranged from 21% to 93%, demonstrating that previous assumptions on the reliability of the technique providing a representative sample for forensic use should be reviewed. This paper highlights the importance of understanding pollen and fabric characteristics when creating a pollen profile in criminal investigations and to ensure that evidence used in testimony is accurate and robust.
自20世纪50年代以来，法医孢粉学在刑事调查中一直发挥着重要作用，常常能提供对识别嫌疑人及确保定罪至关重要的证据。然而，要恰当地使用此类证据，有必要了解影响埋藏学变异性的因素（即花粉粒在法医检查中被发现之前的命运变异性）。在此，我们基于花粉和织物特性，测试了经过一段模拟轻度或重度磨损后衣物上留存的花粉相对量。我们还测试了法医实验室从织物中提取花粉进行分析的协议效率。在任何织物类型上，新鲜或干燥花粉的留存量均无统计学显著差异。根据磨损强度不同，花粉留存量存在显著差异，轻度磨损后留存的花粉比重度磨损后多得多。虫媒授粉物种的花粉留存浓度高于风媒授粉物种的花粉。无论磨损强度如何，这种模式都是一致的，但授粉类型对轻度磨损后花粉留存变异性的解释更多。织物类型与花粉留存显著相关，但与植物物种有强烈相互作用，以至于模式既复杂又具有高度物种特异性。采用标准洗涤协议去除花粉的效率因植物物种、织物类型以及这些因素之间的相互作用而有很大差异。平均效率为67.7%，但范围在21%至93%之间，这表明之前关于该技术为法医用途提供代表性样本可靠性的假设应重新审视。本文强调了在刑事调查中创建花粉图谱时了解花粉和织物特性的重要性，并确保用于证词的证据准确可靠。
