Juror Perceptions of Bystander and Victim Intoxication by Different Substances

• Published date: 01 April 2024
• DOI: http://doi.org/10.1177/00938548241227543
• Author: Natali Dilevski,Hayley J. Cullen,Celine van Golde,Heather D. Flowe,Helen M. Paterson,Melanie K. T. Takarangi,Lauren A. Monds
• Date: 01 April 2024
• Subject Matter: Articles

CRIMINAL JUSTICE AND BEHAVIOR, 2024, Vol. 51, No. 4, April 2024, 569 –587.

DOI: https://doi.org/10.1177/00938548241227543

Article reuse guidelines: sagepub.com/journals-permissions

© 2024 International Association for Correctional and Forensic Psychology

569

JUROR PERCEPTIONS OF BYSTANDER AND

VICTIM INTOXICATION BY DIFFERENT

SUBSTANCES

NATALI DILEVSKI*

Griffith University

HAYLEY J. CULLEN*

The University of Newcastle

CELINE VAN GOLDE

The University of Sydney

HEATHER D. FLOWE

University of Birmingham

HELEN M. PATERSON

The University of Sydney

MELANIE K. T. TAKARANGI

Flinders University

LAUREN A. MONDS

The University of Sydney; Drug and Alcohol Service NSLHD

This study examined the effects of bystander or victim intoxication during a crime on juror perceptions and decision-making.

Mock jurors (N = 261) read testimony from a bystander or victim to an assault, who mentioned that they had consumed

alcohol, cannabis, amphetamines, or no substances prior to the crime. Participants delivered a verdict, rated the defendant’s

guilt, and rated the bystander/victim on their honesty, credibility, and cognitive competence. Witness intoxication and witness

role did not influence defendant guilt. However, participants judged any witness intoxicated by amphetamines as less credible

and cognitively competent than a sober witness. Furthermore, victims were judged to have lower credibility, cognitive com-

petence, and honesty than bystanders. These findings suggest that jurors’ decision-making about defendant guilt might not be

influenced by witness intoxication or witness type. A witness’ testimony, however, might be evaluated as less credible when

delivered by a victim or an amphetamine-intoxicated witness.

Keywords: alcohol and other drugs; intoxication; juror decision-making; credibility; witness evidence

AUTHORS’ NOTE: No funding was provided for the current project. No authors have any conflicts of inter-

est to report. Correspondence concerning this article should be addressed to Natali Dilevski, Centre for

Investigative Interviewing, Griffith Criminology Institute, Griffith University, Nathan, Queensland 4111,

Australia; e-mail: n.dilevski@griffith.edu.au; natali_dilevski@live.com.au.

NATALI DILEVSKI is also affiliated to The University of Sydney.

HAYLEY J. CULLEN is also affiliated to The University of Sydney; Macquarie University.

*N.D. and H.J.C. are joint first authors on this manuscript.

1227543CJBXXX10.1177/00938548241227543Criminal Justice and BehaviorDilevski et al. / Witness Intoxication and Juror Perceptions

research-article2024

570 CRIMINAL JUSTICE AND BEHAVIOR

During a crime, witnesses (i.e., bystanders and victims) may be intoxicated by alcohol

and other drugs (AODs; McNamara et al., 2017). For instance, an Australian Institute

of Health and Welfare (AIHW, 2020) report indicated that 21% of people who had consumed

alcohol had been a victim of an alcohol-related incident (e.g., verbal or physical assault).

Similarly, in a sample of U.S. felony cases referred by police to prosecutors, 20% contained

the testimony of at least one witness who was intoxicated by alcohol during the event (Palmer

et al., 2013). Surveys of police officers from multiple countries indicate that between 24%

and 60% of police interact with people intoxicated by a variety of substances—such as alco-

hol, cannabis, and amphetamines—on a daily or almost daily basis (Monds et al., 2022a; see

also Evans et al., 2009). Taken together, there is evidence to suggest that intoxication among

bystanders and victims is not uncommon at the time an offense occurs.

In Australia, witnesses intoxicated by AOD at the time of an offense are permitted to give

testimony in criminal proceedings, but judgments about their intoxication status may be used

by decision-makers (e.g., jurors) to determine the credibility and reliability of their testimony

(McNamara et al., 2017; Quilter et al., 2022). For instance, defense counsel may argue that a

witness’ account of events is less credible and reliable due to AOD-related memory impair-

ment (e.g., “DJK v Tasmania,” 2017; “R v Crafter,” 2019). Critically, when determining the

effects of AOD intoxication on memory, decision-makers are not typically guided by expert

evidence, but rather, they are directed to draw upon their own common knowledge or per-

sonal experience with AOD intoxication to make such assessments (Quilter & McNamara,

2018). Since jurors may be required to evaluate the testimony of a witness intoxicated by

AOD and base such assessments on “common knowledge,” the purpose of the current study

is to explore mock jurors’ perceptions of the accuracy and reliability of testimony delivered

by a bystander/victim who was intoxicated at the time of an offense.

THE EFFECT OF INTOXICATION ON JUROR PERCEPTIONS

Several studies have used survey methodology to investigate the beliefs that laypeople

hold about how different substances affect memory (e.g., Benton et al., 2006; Cormia et al.,

2022; Desmarais & Read, 2011; Kassin et al., 2001). These studies reveal that alcohol

intoxication is perceived as having a negative effect on memory. In addition, research by

Cormia et al. revealed that while most participants believed cannabis impairs memory, a

sizable minority held the belief that cannabis does not affect memory or enhances memory

(18%–21%).

Other studies have used jury simulation methodology to investigate what effect witness

alcohol intoxication has on juror perceptions of witness credibility and legal decision-making

(e.g., Crossland et al., 2023; Evans & Schreiber Compo, 2010; Ewanation & Maeder, 2018;

Martin & Monds, 2023). In Evans and Schreiber Compo’s study, undergraduate mock jurors

read a description of a case of either a physical or sexual assault, where the person who testi-

fied (either the bystander or victim) was sober, moderately intoxicated, or severely intoxi-

cated at the time of the event. Participants then delivered an individual verdict and answered

questions about the cognitive impairment and credibility of the bystander or victim (depend-

ing on which one testified). Alcohol intoxication resulted in increased perceptions of impair-

ment, which reduced credibility of both the bystander and the victim and lowered guilty

verdicts. Similarly, in the study by Ewanation and Maeder (2018), undergraduate mock

jurors read a trial transcript describing the testimony of a bystander witness who was either

intoxicated (had consumed 10 beers prior to the crime) or sober. Participants delivered a