Abstract
Blood is often used to assist in crime scene reconstruction. It is collected and analysed for identification of individuals associated with a crime scene using molecular analyses. Beyond rudimentary qualitative assessments, the ability to use blood as a biological clock for estimating time since bloodshed (TSB) is limited. When one bleeds following vascular injury, a predicable series of physiological events take place, leading to blood clot formation to curtail the loss of blood. This haemostatic process is complex but highly predicable and offers a reliable model for exploitation to assess TSB. This research looked at a suite of biomarkers associated with clotting to assess their concentration over time, following vascular injury. Prothrombin (PTT), d-dimer and tissue factor (TF) assays were conducted with UV-Vis spectrophotometry and microscopy/cell counting. Multiple surfaces were compared to evaluate the effect of substate type on haemostasis rate. PTT and d-dimer levels in tandem may be useful for identifying bloodshed before/after 1-2 hours when used in tandem. TF appears to be highly susceptible to different surface types while UV-Vis spectrophotometry showed a reproducible trend over 48h.