Verdict spotting: investigating the effects of juror bias, evidence anchors and verdict system in jurors

Abstract

The Scottish verdict of not proven represents a second acquittal verdict which is not legally defined. Existing research into the influence of the not proven verdict on jury decision making is modest. The main aim of the current study was therefore to investigate the influence of verdict systems (two vs three) on juror decision making. The effect of pre-trial bias and evidence anchors on juror judgements were also examined. One-hundred and twenty-eight mock jurors listened to two homicide vignettes and were asked to rate their belief of guilt of the accused and to give a verdict in both trials. The results suggest that pre-trial bias was a significant predictor of both verdict choice and belief of guilt, whereas evidence anchors were not a significant predictor of either. Finally, both guilty and not guilty verdicts were given with increased frequency in the two-verdict system when compared to the three-verdict system.

Proven and not proven: A potential alternative to the current Scottish verdict system

“…a proven and not proven system; . The Scottish verdict system has been reformed several times before it assumed its current form (Barbato, 2004;Curley, Murray, et al, 2021;Duff, 2021;Walker, 1988). The not proven verdict became part of the Scottish legal system through a convoluted, and unplanned, route (Barbato, 2004;Curley, Murray, et al, 2021;Walker, 1988).…”

“…A number of studies have empirically investigated the influence of a two-verdict system (guilty and not guilty) compared to a three-verdict system (guilty, not guilty and not proven) on trial outcomes (Curley, Murray, et al, 2021;Hope et al, 2008;Smithson et al, 2007). For example, Curley, Murray, et al (2021) found that the availability of the not proven verdict decreased the number of guilty verdicts by 38.1% and not guilty verdicts by 74.4%. This suggests that conviction rates could change significantly by moving from a three-verdict system to a two-verdict system.…”

“…These verdicts are ‘guilty’, ‘not guilty’ and ‘not proven’ (Curley, Munro, et al., 2021). The not proven verdict is an acquittal verdict with the exact same legal implications as a not guilty verdict (Curley, Murray, et al., 2021). The current three‐verdict system is currently being publicly debated by stakeholders, including citizen activists and legal professionals, and the major political parties in Scotland have voiced support for either abolition or review of the not proven verdict (Richardson & Gardiner, 2021).…”

“…The Scottish verdict system has been reformed several times before it assumed its current form (Barbato, 2004; Curley, Murray, et al., 2021; Duff, 2021; Walker, 1988). The not proven verdict became part of the Scottish legal system through a convoluted, and unplanned, route (Barbato, 2004; Curley, Murray, et al., 2021; Walker, 1988). Before the late 17th century, Scottish juries could indicate their belief in the accused's guilt or innocence, although there was a lack of consistency in the wording (Barbato, 2004; Walker, 1988).…”

“…guilty and not guilty) in the first half of the 18th century. However, the not proven verdict was retained, thus creating the current three‐verdict Scottish system (Barbato, 2004; Curley, Munro, et al., 2021; Curley, Murray, et al., 2021; Curley, MacLean, Murray, Laybourn, et al., 2019; Smith & MacDonald, 1958).…”