The use of a forensic blood substitute for impact pattern area of origin estimation via three trajectory analysis programs

ABSTRACT This study explores the use of forensic synthetic blood substitute (FBS) for impact pattern simulation and area of origin estimation. Ten impact patterns were created at a known origin using the FBS and were analyzed by groups of undergraduate students participating in a basic bloodstain pattern analysis course. The students selected 20 upward-moving stains from their given patterns to estimate an area of origin. Three linear trajectory models – BackTrack™, Hemospat, and Sherlock – were used to estimate each pattern's area of origin. Coordinate data from each model's analysis were compared with the known origin and between programs at the x-, y-, z-coordinates, and overall. Results from this analysis yielded estimates comparable to the known. A one-way ANOVA found no significant difference between programs at the x- (p = 0.79), y- (p = 0.84), z- (p = 0.96) coordinates, and overall (p = 0.81). These results support the practical use of the FBS as an alternative to whole blood for impact pattern simulations and area of origin estimation.