Paper detail

Confirmative laboratory tests and one example of forensic application of the probabilistic approach to the area of convergence in BPA

One of the most important results in Bloodstain Pattern Analysis (BPA) is the determination of the area of convergence of blood-drop trajectories. This area is directly related to the point of origin of the projections and is often indicative of the point where the main action of a crime has occurred. One of us has recently proposed a method to statistically characterize this area by mean of a probabilistic approach based on the uncertainties of the angles of impact of the stains in the pattern. In our work we present some laboratory tests that confirm the validity of the method, returning good agreement between the empirical and the theoretical data. By comparing the results of different operators, we also show the robustness of the method, in that the results are independent of the analytical approach of the single experimenter. Finally, we describe an example of application to a real forensic case.