Date of Award
Bachelor of Arts Honours
Faculty of Health and Human Sciences
The provision of expert testimony for the defence has been demonstrated to sensitise jurors to the variables that may reduce the reliability of an eyewitness identification (Cutler, Dexter, & Penrod, 1989). However, research examining the variables that reduce identification reliability has revealed conflicting findings (Yuille & Cutshall, 1986). Given this disparity in psychological opinion, a situation may arise where opposing expert testimony for the prosecution and the defence is delivered within the same criminal trial This thesis examined the effect of each form of expert testimony about eyewitness identification issues on the decision of the individual juror. The decision making process was divided into three stages. The first stage was defined as the ability to draw accurate inferences about the credibility of the eyewitness, the accused, and the strength of the case for the prosecution and the defence. The second stage was defined as the ability to critically evaluate information that is presented about the eyewitness identification. The third stage was defined as the ability draw accurate judgements in relation to the reliability of the identification, and the verdict. Participants (N= 104) constituted a sample of eligible jury members within the general population. A trial transcript was delivered whereby the accused was charged with the armed hold-up of a service station. The crucial evidence constituted the positive identification of the accused by' the victim or the crime. Witnessing and identification conditions were described as being conducive to a false identification. The expert witness for the prosecution submitted empirical evidence that portrayed the identification as reliable. The expert witness for the defence delivered equivalent information that portrayed the identification as lacking in reliability. Findings demonstrated that alternative modes or expert testimony failed to influence the type of decision formed by the individual juror. Despite this finding of no difference, all subjects demonstrated an inability to form accurate inferences in relation to the credibility of the accused, and the strength of the case for the prosecution. Furthermore, all subjects failed to demonstrate evidence for the critical evaluation of information presented in relation to witnessing and identification conditions. As a consequence, subjects were unable to form an accurate judgement in relation to the reliability of the identification. It is submitted that the provision of expert testimony for the prosecution, and the provision of expert testimony for the defence, facilitates a juror scepticism effect. It is concluded that where evidence of a scepticism effect exists, the probability of wrongfully acquitting an otherwise guilty individual will substantially increase.
Sullivan, P. J. (1996). The Effect of Expert Testimony on Juror Decision Making in Eyewitness Identification Cases. Retrieved from http://ro.ecu.edu.au/theses_hons/727