Bloodstain Pattern Analysis on Various Surfaces Using Simulated Blood: A Forensic Approach

Abstract

Background: Bloodstains are commonly encountered biological evidence at the crime scenes. Bloodstain pattern analysis provides crucial information about height of fall, angle and force of impact assisting in crime scene reconstruction. Objective: The present study was conducted to evaluate the inÁuence of surfacecharacteristics and height of drop of fall of blood drop on various porous and nonporous surfaces on bloodstain pattern analysis for forensic purpose. Methodology: In the present study, simulated blood was prepared using red water color and cornÁour homogenized with distilled water to attain the consistency nd appearance of real blood avoiding ethical implications associated in using real blood. The experiment was conducted to examine the bloodstain patterns formed on various porous (paper, cardboard and soil) and non-porous (glass, metal and tile) surfaces when simulated blood was dropped passively from various heights with a constant impact angle of 90º. The experiment was carried out in triplicate. The bloodstains were analyzed for the shape, size and distribution. Results: The results showed an increase in size of the stain with increase in height of fall across all surfaces. Depending on point of impact, soil showed different bloodstain patterns while paper and cardboard due to their absorbent nature displayed larger stains with prominent satellite stains and spikes on the edges of the central stain. Non-porous surfaces displayed more uniform smaller stains with no spikes on the edges and few secondary stains. Conclusion: Simulated blood can be used as an effective, ethical and safer substitute to real blood for employing in training, research and forensic experimentations.