By Dr Gianni Ribeiro


Jury deliberation is considered a cornerstone of fair trial proceedings. However, a newly published study in Frontiers in Psychology in January 2024, which I co-authored, delves into a crucial issue: the potential for jurors to misremember key evidence from the trial and introduce misinformation during deliberations.


Image by OpenClipart-Vectors from Pixabay

The problem of memory distortion is well-documented in the context of eyewitness testimony, where misinformation can compromise the reliability of witness accounts (see Loftus, 2005, for a review). Discussion among eyewitnesses is a known source of memory distortion and can result in memory conformity, where each eyewitnesses’ account of the event starts to resemble other eyewitnesses’ accounts. As a result, discussion between eyewitnesses is discouraged in efforts to preserve memory integrity. However, in jury deliberations, it is assumed that discussions will enhance jurors’ memory of the key details relating to the case, leading to more accurate verdicts (Pritchard and Keenan, 1999, 2002; Hirst and Stone, 2017; Jay et al, 2019).

Before our research, only one study had explored whether misinformation introduced in jury deliberations affected juror memory and decision-making (Thorley et al, 2020). They found that the more misinformation mock jurors accepted (ie, misremembered it as evidence from the trial), the more likely they were to reach a guilty verdict.


Our research builds on Thorley and colleagues’ (2020) work by also exploring the effect of pro-defence misinformation and whether judicial instructions warning jurors about misinformation may mitigate its influence in a sexual assault trial.

In our first study, we found that participants were more likely to misremember pro-prosecution misinformation as having been presented as evidence during the trial compared to pro-defence misinformation. However, misinformation did not impact ultimate decision-making in the case, which may be attributed to most participants (87.6%) leaning towards a guilty verdict prior to deliberation.

Therefore, in our second study, we used a more ambiguous case that resulted in a more even split of verdicts pre-deliberation (66.7% guilty). Here, we found that participants who received pro-defence misinformation were more likely to misattribute the misinformation as coming from the trial than participants who received pro-prosecution misinformation. Further, pro-defence misinformation led to a decrease in ratings of defendant guilt and complainant credibility, and an increase in the strength of the defendant’s case. However, the judicial instruction about misinformation exposure had no effect.


Together, the findings from our two studies suggest that misinformation introduced during jury deliberations may indeed distort memory of trial evidence and impact decision-making. Although there is popular support for judicial instructions as a legal safeguard, there is mixed evidence for their effectiveness and our research found that there was no effect of warning jurors about potential misinformation prior to deliberation. These findings call for a deeper exploration of strategies to maintain the integrity of juror deliberations and ensure the fairness of trial verdicts.

The article is open access, so you can read and download it for free here.


Gianni Ribeiro is a Lecturer in Criminology in the School of Law and Justice at the University of Southern Queensland. She is based at the Ipswich campus.

Prior to joining the School of Law and Justice in 2023, Gianni obtained her PhD in applied cognitive and social psychology from The University of Queensland in 2020 with no corrections. She was a Postdoctoral Research Fellow in the School of Psychology at the University of Queensland working in collaboration with Queensland Police Service.