在法医环境中,稀释的血迹经常遇到,例如,当血迹与胶带/雨水混合时,经过深思熟虑的清洁尝试,或当血液滴在湿的表面,如毛巾。这种稀释的血迹情况可以细分为一系列事件,其中血滴被(1)容易稀释(血液和水的混合物沉积);(2)沉积在容易润湿的表面上(第一水,然后是血液)或(3)沉积并随后润湿(第一次血液,然后是水)。当前的血迹模式分析(BPA)缺乏数据和工具来区分这三种衍生稀释血迹的方法,这些方法在血液和水在纺织品上的沉积顺序上有所不同。在这项研究中,检查了880个血迹的特征,这些特征可用于确定稀释血迹的来源。提取了帮助BPA分析师解释稀释血迹的指南。通过进行两项调查确认了该指南的附加价值:一项有指南的调查和一项无指南的调查。第三项调查证实,这些特征也适用于具有不同编织和针织风格的更广泛的纺织品类型。该指南可以帮助BPA专家确定,以客观的方式,稀释的血迹是如何产生的,这有助于确定哪些活动发生在犯罪现场。
In forensic settings, diluted bloodstains are regularly encountered for example when bloodstains are mixed with tap-/rainwater, after deliberate cleaning attempts, or when blood is dropped on a wet surface such as a towel. Such diluted bloodstain scenarios can be subdivided into sequences of events in which a blood drop was either (1) readily diluted (a mixture of blood and water is deposited); (2) deposited on a surface that was readily moistened (first water, then blood) or (3) deposited and subsequently moistened (first blood, then water). Current bloodstain pattern analysis (BPA) lacks data and tools to distinguish these three ways of derivation of a diluted bloodstain that vary in the sequence of deposition of blood and water on textile. In this study, 880 bloodstains were examined for characteristics that can be used to determine the derivation of diluted bloodstains. A
guideline to assist BPA-analysts in interpreting diluted bloodstains was extracted. The added value of this
guideline was confirmed by conducting two surveys: one survey with and one without the
guideline. A third survey confirmed that the characteristics also function on a broader range of textile types that have different weave and knit styles. This
guideline can aid BPA-experts to determine, in an objective way, how diluted bloodstains derived which can aid in determining which activities took place at a crime scene.