One-hundred-and-twenty-five mock jurors rated the credibility of video testimony of 17 autistic and 17 TD witness participants recalling an event. Half of the juror participants were informed that some of the witnesses were autistic and were provided with information about autism; the other half received no information about witnesses’ diagnoses. Results indicate that disclosing one’s autism diagnosis (alongside further information about autism) may result in a positive bias in terms of witnesses’ perceived credibility. Implications for jury instructions and future research directions are discussed. People with autism spectrum disorder (henceforth, autism) exhibit a number of atypical behaviours that may be relied upon by jurors when making judgements about their credibility as witnesses. The current study aimed to: (1) examine whether autistic witnesses were perceived as less credible than typically developing (TD) witnesses, irrespective of the number of correct details they reported; and (2) determine whether mock jurors’ credibility ratings of autistic witnesses improved if they were aware of their autism diagnoses and were provided with information about autism. Contrary to predictions, autistic witnesses were seen to be as credible as TD witnesses when no information about their diagnosis was provided. However, when jurors were informed that a witness was autistic and were also provided with further information about autism, they were rated as slightly more credible than TD witnesses. Credibility ratings were only predicted by jurors’ prior knowledge/experience of autism when they were explicitly informed of witnesses’ autism diagnoses.

Videos of autistic and typically developing (TD) witnesses were taken from a previous experiment (Maras et al., 2013). Here, the experimenter and witness participant each performed several actions on a road traffic accident mannequin and were subsequently interviewed for their memory of the event. Interviews comprised two aspects: free recall and subsequent questioning (as per Achieving Best Evidence guidelines, Home Office, 2011). The final sample of witness participants comprised 17 autistic witnesses and 17 TD witnesses.