The aim of this study was to identify factors that improve jury understanding and use of inculpatory DNA evidence; that is, evidence that links a suspect to a crime. A quasi-randomised, between-subjects factorial design compared five experimental groups of virtual jurors. The first factor, presence of an expert, compared outcomes in a case with no expert versus a single expert. The second factor, mode of presentation of expert evidence, compared outcomes following exposure to an expert tutorial presented verbally, with partial multimedia, or with full multimedia. The study tested whether:

• expert evidence enhances juror DNA knowledge;
• visual information enhances understanding compared to information conveyed verbally;
• strong DNA evidence increases conviction rates compared to inconclusive DNA evidence; and
• greater understanding of DNA evidence reduces convictions