Intoxicated witnesses and suspects: An archival analysis of their involvement in criminal case processing.

Abstract

Research about intoxicated witnesses and criminal suspects is surprisingly limited, considering the police believe that they are quite ubiquitous. In the present study, we assessed the involvement of intoxicated witnesses and suspects in the investigation of rape, robbery and assault crimes by analyzing cases that were referred by the police to a prosecutor's office. Results indicated that intoxicated witnesses and suspects played an appreciable role in criminal investigations: Intoxicated witnesses were just as likely as sober ones to provide a description of the culprit and to take an identification test, suggesting criminal investigators treat intoxicated and sober witnesses similarly. Moreover, intoxicated suspects typically admitted to the police that they had consumed alcohol and/or drugs, and they were usually arrested on the same day as the crime. This archival analysis highlights the many ways in which alcohol impacts testimony during criminal investigations, and underscores the need for additional research to investigate best practices for obtaining testimony from intoxicated witnesses and suspects.

The Effects of Alcohol Intoxication on Accuracy and the Confidence–Accuracy Relationship in Photographic Simultaneous Line‐ups

“…Police surveys and archival research indicate that intoxicated witnesses and victims often provide police statements and take identification tests in criminal investigations (Evans, Schreiber Compo, & Russano, 2009; Palmer, Flowe, Takarangi, & Humphries, 2013). Yet, relatively few line‐up studies have examined the impact of alcohol on identification accuracy (Hagsand, Roos af Hjelmsäter, Granhag, Fahlke, & Söderpalm‐Gordh, 2013; Harvey, Kneller, & Campbell, 2013; Kneller & Harvey, 2016; Yuille & Tollestrup, 1990).…”

“…We also tested whether alcohol consumption and/or alcohol expectancy (i) weakens the confidence–accuracy relationship, as per the optimality hypothesis, or (ii) strengthens the confidence–accuracy relationship as per Palmer, Brewer et al's (2013) theory‐based information model of the confidence–accuracy relationship.…”

Mind the Gap: The Key to Advancing the Science and Policy on Alcohol-Intoxicated Witnesses is to expand the Study Population and Bridge the Researcher-Practitioner Gap

“…It is unclear if this is being conducted today, but 71% of US law enforcement officers reported several years ago that they do not measure the witnesses' intoxication level in an objective manner [5]. Similar, as noted by Palmer et al [6], police officers in the US usually determined that a witness had consumed alcohol or another drug because the witness reported this (in 88% of the cases). Few officers took a breathalyzer test (9%), or observed the witness engaging in alcohol or other drug intake (3%).…”

“…A law-enforcement survey and an archival study found that alcohol-intoxicated witnesses to crimes are highly prevalent [5,6]. The survey of US police officers showed that intoxicated eyewitnesses were most commonly encountered in violent crimes, such as fights, domestic disputes, assaults, thefts and disorderly conduct.…”

“…Investigative interviews with intoxicated witnesses were conducted on average five times a week [5]. Further, it seems to be a common belief among practitioners within the legal system that intoxicated eyewitnesses are less credible than sober eyewitnesses [6][7][8]. Given the high prevalence of intoxicated witnesses, it may seem surprising that so little research has been conducted on this topic.…”