Winnepenninckx Astrid, Verhoeven Elke, Vermeulen Steve, Bekaert Bram
KU Leuven, Forensic Biomedical Sciences, Department of Imaging & Pathology, Leuven, Belgium.
Technical and Scientific Police, Federal Judicial Police, Leuven, Belgium.
Forensic Sci Int. 2022 Feb;331:111167. doi: 10.1016/j.forsciint.2021.111167. Epub 2021 Dec 23.
The localization of latent blood traces at crime scenes is generally performed using fluorescent stains although infrared light has previously been recognized as an effective localization test for bloodstains as it is a non-destructive and non-contact technique. The goal of this study was to evaluate infrared photography for the detection of latent bloodstains on a large number of objects with different compositions frequently encountered at crime scenes. In this study we show that infrared light photography was able to detect bloodstains deposited on 71.7% of materials while bloodstains on 29.2% of materials could only be detected using infrared photography and not through visual photography. Bloodstain could be detected on most fabrics composed of 100% polyester, 100% cotton and 100% wool or a combination of these fibers with other types of fiber such as nylon or viscose. For other materials such as leather, tiles, wood, bricks, parquet, infrared did not improve the visibility of the bloodstains. Finally, the influence of the time of bloodstain deposition was tested over the period of 1 week and 1 month and did not reveal major differences compared to stains after 24 h drying time suggesting that time has little influence on the ability of infrared light and visual light to detect latent bloodstains.
犯罪现场潜在血迹的定位通常使用荧光染色剂来进行，尽管红外光此前已被公认为是一种有效的血迹定位检测方法，因为它是一种非破坏性且非接触式的技术。本研究的目的是评估红外摄影技术在检测犯罪现场大量不同成分物体上的潜在血迹方面的效果。在本研究中，我们发现红外光摄影能够检测出沉积在71.7%的材料上的血迹，而有29.2%的材料上的血迹只能通过红外摄影而非视觉摄影来检测。在大多数由100%聚酯、100%棉花、100%羊毛或这些纤维与其他类型纤维（如尼龙或粘胶纤维）组合而成的织物上都能检测到血迹。对于皮革、瓷砖、木材、砖块、镶木地板等其他材料，红外光并不能提高血迹的可见度。最后，我们测试了血迹沉积时间在1周和1个月内的影响，结果表明与干燥24小时后的血迹相比，未发现显著差异，这表明时间对红外光和可见光检测潜在血迹的能力影响很小。
