At the scene of violent crimes, bloodstain evidence is one of the most frequently found and valuable types of evidence. Determining the time since deposition (TSD) can allow for investigators to draw conclusions as to when a crime occurred. In this proof-of-concept study Raman spectroscopy paired with chemometrics were utilized for the prediction of TSD for bloodstains aged under an extreme thermal environment (55 °C) up to 48 h post deposition. This temperature was chosen to represent an internal condition of a vehicle left in direct sunlight. It was found that peripheral bloodstains degraded at a faster rate when exposed to an extreme thermal environment than when aged under ambient conditions. TSD quantitative predictions were accomplished through the creation of two classification models.

在暴力犯罪现场，血迹证据是最常见、最有价值的证据之一。确定自作证以来的时间 (TSD) 可以让调查人员得出犯罪发生时间的结论。在这项概念验证研究中，拉曼光谱与化学计量学相结合，用于预测沉积后在极端热环境 (55 °C) 下长达 48 小时的血迹的 TSD。选择该温度来代表处于阳光直射下的车辆的内部状况。研究发现，与在环境条件下老化相比，暴露在极端热环境中时外周血迹的降解速度更快。TSD 定量预测是通过创建两个分类模型来完成的。