Date of Award


Degree Name

Doctor of Philosophy



First Advisor

Peter-Hagene, Liana

Second Advisor

Jacobs, Eric


AN ABSTRACT OF THE DISSERTATION OFChasity Ratliff, for the Doctor of Philosophy degree in Psychology, presented on June 22, 2020, at Southern Illinois University Carbondale. TITLE: CONTENT VARIATION IN JURY INSTRUCTIONS FOR FATAL POLICE USE OF FORCE TRIALS DO NOT MODERATE THE EFFECT OF ATTITUDES TOWARD POLICE ON VERDICTSMAJOR PROFESSOR: Liana C. Peter-HageneWhen police officers are charged with illegal use of force, jurors’ pre-existing attitudes toward the police can shape how jurors interpret trial evidence: Was the officer just doing his job under high amounts of pressure while fearing for his life? Or did the officer abuse his power with disregard for the victim’s life? The language in jury instructions, however, might reduce or exacerbate the effect of jurors’ attitudes toward police on their verdict decisions. In an experimental mock-jury study, the content of jury instructions was manipulated to be consistent with an objective standard of reasonableness (i.e., Tennessee v. Garner, 1985) or a subjective standard of reasonableness (Graham v. Connor, 1989), along with a control condition with no police-specific language. I predicted that, compared to control instructions, objective standards would weaken, and subjective standards would strengthen, the influence of attitudes on verdicts. Attitudes toward police were measured as a continuous predictor and were counterbalanced before and after the trial. An online sample of individual mock-jurors (N = 539) viewed a trial presentation in which a police officer was charged with first-degree murder for illegal use of force. The importance of prosecution evidence and the extent to which they took the officer’s perspective were potential mediators of the relationship between attitudes and verdicts. As predicted, jurors’ negative (versus positive) attitudes toward police predicted the importance of prosecution evidence, and perspective-taking. In turn, the importance of prosecution evidence and perspective-taking predicted juror’s perceptions of officer guilt. Instruction content was not a successful moderator of the relationship between attitudes and verdicts. The effect of attitudes on verdicts in fatal police use of force trials has important implications for the psychological study of jury decision-making, and for the criminal justice system as a whole. Key Words: fatal police use of force; attitudes; attitudes toward police; juror verdict decisions; jury instructions; subjective and objective standards.




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