3D scanning a crime scene to enhance juror understanding of Bloodstain Pattern Analysis evidence

Abstract

There are numerous crime scene investigation applications of 3D scanning that have been previously documented. This paper documents the application of a 3D point cloud in the presentation of Bloodstain Pattern Analysis evidence to mock jurors. 150 mock jurors viewed a presentation of Bloodstain Pattern Analysis evidence from a murder trial in the UK. After viewing the evidence, the participants were tested on their knowledge of the evidence and repeated the test again 2 weeks later; to simulate criminal trial conditions; whereby there is a time lapse between the initial viewing of evidential material and deliberation. This paper found that the mock jurors who additionally viewed a 3D flythrough of a point cloud of the crime scene, better retained knowledge of the evidence over time, reported a greater ability to visualise the crime scene and had higher levels of interest in the evidence. Crucially, the 3D flythrough group did not report different levels of confidence in the accuracy of their memories of the evidence, nor different levels of emotional arousal to the group that viewed the evidence without the 3D presentation. Together, these findings suggest that 3D scanning of crime scenes, and the resultant point cloud's presentation to jurors, could add further value to the justice system when spatial information, such as Bloodstain Pattern Analysis evidence, is presented.

Keywords: Bloodstain Pattern Analysis; Crime Scene; Expert Witness; Forensics; Jury; Justice.