Use of the Backtrack™ Computer Program for Bloodstain Pattern Analysis of Stains from Downward-Moving Drops

ABSTRACT Using Directional Analysis, the BackTrack™ suite of computer programs can be used to analyze a crime scene in which bloodstains only from downward-moving drops are available. Only two of three Cartesian coordinates for the blood source location can be accurately determined, but this is still significantly better than the stringing and tangent methods, which cannot accommodate the stains from downward-moving drops without great difficulty. Crime scene investigators with access to this computer program should be aware of the program's ability to use data that cannot be used easily in other methods of analysis.