Comparison of real blood and synthetic blood for blood spatter pattern determination on various matrices

Abstract

Blood is a significant evidence associated with forensic investigation as bloodstain pattern analysis helps establish specific events associated with crimes. The study involved the comparison of bloodstain patterns of real blood and synthetic blood on various solid matrices. Bloodstain appearance and dimensions were studied in terms of release height, directionality, angle of impact and area of impact. Results showed that shapes and sizes of blood drops differ as the heights of release, angles impact and surface matrices were changed, but there were only minor differences between real and synthetic blood. Sizes of blood drops increased with release height, but the increase was more pronounced for synthetic blood. The multiple impact sites, origin and point of divergence study on droplets of real blood and synthetic blood as determined using mathematical methods showed that for medium velocity droplets, synthetic blood gave higher angles. However, at high velocity, the angles were almost equal for both real and synthetic blood. For both real and synthetic blood, the angles were approximately 17o-43o for all sides, except for the center of the high velocity droplets which were 90o.