Recovery of Bloodstain Patterns from Arson Scenes: Does Soot Removal Using Liquid Latex Damage Underlying Bloodstains?

Abstract

Although traditionally perceived as a fruitless task due to the destructive nature of the fire and subsequent fire suppression efforts, evidence recovery from an arson scene, whether a crime in itself or as concealment for another, is paramount. The importance of this recovery is echoed by recent literature concerning post-arson evidence recovery, as it is demonstrated that certain types of evidence are more likely to survive than first thought, and that their recovery often depends on the effective removal of overlying soot. This investigation concerns the application of liquid latex for soot removal to facilitate the detection and examination of bloodstain patterns, which may be used to reconstruct events prior to or during the fire. Due to the nature of bloodstain pattern analysis and its reliance on the size and shape of the bloodstains, the primary goal was to evaluate any damaging effects that the liquid latex application and removal process may have on the underlying bloodstains and bloodstain patterns. Bloodstains in this study were projected onto a number of different surfaces of varying porosity and texture and subjected to a fire environment allowing a layer of soot to form, followed by the removal of the soot using liquid latex. It has been concluded that sprayed liquid latex is able to remove soot while preserving underlying bloodstains with varying degrees of success depending on the surface type. It is thought that a finer mist produced by higher quality equipment, as employed in previous investigations, may increase the success of this technique on the surfaces of lower porosity.