Perceived infallibility of detection dog evidence: implications for juror decision-making

ABSTRACT

This study focuses on the trust that potential jurors have in unsubstantiated evidence and the implications of such trust for legal decision-making. We examined whether participants’ motivation to think deeply (‘need for cognition,’ NC) and belief in science moderated their trust in potentially fallible detection dog evidence when selecting a verdict in a trial scenario. A detection dog twice indicated the presence of drugs in the scenario, yet no drugs were actually found. Those who chose a guilty verdict without drugs present featured stronger beliefs in detection dog evidence. They were also more confident that a dog alert indicated the presence of drugs, even though the scientific literature actually shows that detection dog evidence is subject to biases and other challenges to reliability. Our findings indicate that an unsubstantiated belief and trust in detection dog evidence may negatively influence juror decision-making, which may, in turn, pose consequences for fairness and justice. Participants believed that detection dogs provide powerful and reliable evidence, and these beliefs were clearly associated with stronger beliefs in science. These findings, therefore, raise serious concerns about jurors’ indiscriminate trust in forensic evidence, be it detection dog evidence or other lines of evidence presented in court.

KEYWORDS:

• Mythic infallibility
• detection dog
• jury decision making
• forensic evidence
• sniff evidence
• bias

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the University of California Davis [Academic Federation Innovative Development Award].

Notes on contributors

Lisa Lit

Lisa Lit received her MA in Experimental Psychology at California State University, San Bernardino and her PhD in Genetics at the University of California, Davis.  Her work has encompassed genetic bases of neurodevelopmental, neurological, and behavioral disorders, as well as cognitive factors underlying human-dog relationships and working dog performance.  In addition to continuing work on human-dog relationships through an ongoing affiliation with Dr. Anita Oberbauer at UC Davis, she is currently involved in studying effects of childhood trauma in criminal justice populations.

Anita Oberbauer

Dr. Anita Oberbauer is a geneticist studying physiological and behavioral traits.  She received her B.S. in Zoology from the University of California, Davis, PhD from Cornell University, and then completed postdoctoral fellowships in perinatal biology and biological chemistry prior to joining the faculty at the University of California, Davis.  Her work has targeted canine genomics including investigations into epilepsy and hypoadrenocorticism, as well as having a fruitful collaboration with Dr. Lisa Lit on working dog behavior and human-dog interactions.

James E. Sutton

James E. Sutton received his PhD in Sociology, with an emphasis in Crime and Community, from the Ohio State University.  His published works have examined a range of topics, including sexual assault in prison, gangs, prison ethnography, state corporate offending, and the use of life events calendars to improve the reliability and validity of self-reported interview data.  He is currently Chair of the Department of Sociology, Chair of the Institutional Review Board (IRB), and an Associate Professor of Sociology at Hobart and William Smith Colleges in Geneva, New York.

Itiel E. Dror

Dr. Itiel E. Dror is a cognitive neuroscientist who received his PhD from Harvard in the area of cognitive factors in human expert performance.  His insights and understanding of the human brain and cognitive system underpin his applied work with U.S. Air Force pilots, policing, medical experts, as well as forensic scientists and experts in other domains.  His research has demonstrated that specific components in the cognitive underpinning of expertise entail vulnerabilities.  In the forensic domain Dr. Dror has led to the understanding that the perceptions and cognitions of the human examiner play a key role in forensic work.  Building on these insights he developed unique ways to combat these weaknesses and improve expert performance.  Dr. Dror has published over 120 peer-reviewed articles specifically looking at cognitive factors that mediate human expert performance, and he has trained police and forensic examiners in numerous countries.  More information is available at: www.cci-hq.com.