Using multimedia to support jury understanding of DNA profiling evidence

Abstract

Jury difficulties in understanding and according suitable weight to probabilistic scientific expert evidence about DNA profiling are well established. Traditional legal aids, including note-taking and allowing jury questions, have had limited success in diminishing their problems. This study examined the potential of multimedia instruction to enhance jury comprehension. Mock jurors reviewed a homicide case in which DNA evidence linked the suspect to the crime scene. Instructional media on ‘Forensic DNA Technology’ and/or ‘Random Match Probability’ accompanied the oral expert evidence to support juror understanding. Pre-test–post-test comparisons of juror conceptions about forensic uses of DNA determined whether these multimedia facilitated juror comprehension. Analyses of responses to the expert evidence acknowledged the incidence of ‘CSI’ effects in which jurors have increased expectations of scientific evidence after viewing popular crime investigations on television. Since multimedia instruction for juries can apply to all forms of forensic evidence, we propose the use of structured instructional media for courts developing policies on uses of visual evidence.