Ecole des Sciences Criminelles, University of Lausanne, Switzerland.
Ecole des Sciences Criminelles, University of Lausanne, Switzerland.
Forensic Sci Int. 2021 Aug;325:110847. doi: 10.1016/j.forsciint.2021.110847. Epub 2021 May 24.
Condom evidence has become in the past years a very relevant item of evidence in sexual assault or rape cases, being an objective help in the reconstruction of the activity. Traces recovered from a vaginal swab might help to identify whether a condom or other lubricants were used, and thereby possibly confirming or infirming allegations of the parties. However, the interpretation of condom traces can be challenging and requires a detailed understanding of various factors like condom lubricant chemical composition and occurrence on the market, transfer and persistence parameters and background. Herein, we aimed at improving our understanding of factors affecting the transfer variability of condom residues recovered from vaginal matrix. This work employed Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) to provide new data for a characterization of condom lubricants and their traces after a transfer in a vaginal matrix has occurred. Condom traces were recovered from volunteers and the traces characteristics were investigated and analyzed. The effects of donor (condom) and receiver (vaginal matrix) were firstly evaluated, as they are known factors, and these data that could be obtained in real caseworks. Using principal component analysis (PCA), this study highlighted that the effect of the donor was more important than the receiver effect. Vaginal matrix residues were not detected in transferred extracts. The discrimination pattern amongst the donor was found to be indistinguishable from the one obtained on reference material using ATR-FTIR (Attenuated Total Reflectance).
在过去几年中，避孕套证据已成为性侵犯或强奸案件中非常重要的证据，为活动重建提供了客观帮助。从阴道拭子中回收的痕迹可能有助于确定是否使用了避孕套或其他润滑剂，从而可能证实或反驳当事人的指控。然而，避孕套痕迹的解释具有挑战性，需要详细了解各种因素，如避孕套润滑剂的化学成分和市场上的出现情况、转移和持久性参数以及背景。在此，我们旨在提高对影响从阴道基质中回收的避孕套残留物转移可变性的因素的理解。这项工作采用漫反射红外变换光谱（DRIFTS）来提供避孕套润滑剂及其在阴道基质中转移后的特征描述的新数据。从志愿者中回收避孕套痕迹，并对痕迹特征进行了调查和分析。首先评估了供体（避孕套）和受体（阴道基质）的影响，因为它们是已知因素，并且这些数据可以在实际案例中获得。使用主成分分析（PCA），本研究强调供体的影响比受体的影响更为重要。在转移的提取物中未检测到阴道基质残留物。从供体获得的区分模式与使用ATR-FTIR（衰减全反射）获得的参考物质的区分模式无法区分。
