The detrimental impact of alcohol intoxication on facets of Miranda comprehension.

Abstract

Objective: Law enforcement officers often encounter alcohol-intoxicated suspects, suggesting that many suspects are presented with the challenge of grasping the meaning and significance of their Miranda rights while intoxicated. Such comprehension is crucial, given that Miranda is intended to minimize the likelihood of coercive interrogations resulting in self-incrimination and protect suspects’ constitutional rights. Yet, the effects of alcohol on individuals’ ability to understand and appreciate their Miranda rights remain unknown—a gap that the present study sought to address. Hypotheses: Informed by alcohol myopia theory (AMT), we predicted that intoxicated individuals would demonstrate impaired Miranda comprehension compared to sober individuals and those who believed they were intoxicated (but were in fact not; i.e., placebo participants). Method: After health screenings, participants completed the Wechsler Abbreviated Scale of Intelligence–Second Edition verbal subtests, rendering a Verbal Comprehension Index (VCI) score. We randomly assigned participants to consume alcohol (n = 51; mean breath alcohol concentration [BrAC] = 0.07%), a placebo condition (n = 44; BrAC = 0.00%), or a sober control condition (n = 41; BrAC = 0.00%). All participants (N = 136) completed the Miranda Rights Comprehension Instruments (MRCI), which measured participants’ understanding of the Miranda warnings, recognition of the warnings, appreciation of their rights in interrogation and court settings, and understanding of Miranda-related vocabulary. Results: We found a significant effect of intoxication condition on participants’ understanding of Miranda warnings (η p2 = .14) and Miranda-related vocabulary (η p2 = .05) when controlling for VCI scores. Specifically, intoxicated participants received lower scores for understanding of warnings compared to sober and placebo participants, and lower scores for understanding of Miranda vocabulary compared to sober participants. Alcohol did not significantly impact Miranda rights recognition or appreciation. Conclusions: Alcohol intoxication may detrimentally impact some facets of Miranda comprehension. Thus, it is important that law enforcement consider refraining from questioning intoxicated suspects.

The impact of alcohol intoxication and short-sighted decision making in the interrogation room.

“…The current procedures and data are part of a larger study. Some data have already been published elsewhere (Meldrum et al, 2023;Mindthoff et al, 2021Mindthoff et al, , 2022. Procedures not relevant to the present article are not described here.…”

Forensic assessment instruments: Their reliability and applicability to criminal forensic issues

“…The Court also held that valid waivers may be implied by a suspect's actions as well as words ( Berghuis v. Thompkins , 2010). Psychological factors relevant to determinations of waiver validity include acute intoxication (Mindthoff et al., 2022), intellectual capacity (Erickson et al., 2020), and maturity (Zelle et al., 2015).…”

Police–suspect interactions and confession rates are affected by suspects’ alcohol and drug use status in low-stakes crime interrogations

“…However, we urge future research to find novel ways to examine how intoxication and substance use status at the time of the crime affect subsequent police-suspect interaction and outcomes of the interrogation such as confession or denials, as there is evidence that alcohol/drug status at the time of the crime can affect other legal practitioners such as judges (e.g., Spohn et al, 2014). Also, emerging 10.3389/fpsyg.2022.983362 evidence suggests that intoxicated lab participants may have difficulties in understanding Miranda rights (Mindthoff et al, 2022), with implications for intoxicated suspects' comprehension of these rights if interrogated in close temporal proximity to the crime.…”

“…Crimes related to alcohol or narcotics are common worldwide and, according to police surveys, suspects are often intoxicated both when arrested and during interrogation (Evans et al, 2009;Monds et al, 2021;Hagsand et al, 2022a). Intoxication may also make suspects vulnerable in legal contexts (see Mindthoff et al, 2018Mindthoff et al, , 2020Mindthoff et al, , 2022. Further, in Sweden where the present study was conducted, in 2020 a majority (58%) of inmates suffered from substance use disorder (Swedish Prison and Probation Service, 2021) and similar results have been found in other countries such as the United States (National Center on Addiction and Substance Abuse at Colombia University, 2010).…”

“…To date, most research on the potential effects of alcohol on memory of criminal events has concerned witnesses’ memory, and not that of suspects (but see Mindthoff et al, 2022 ). Both police officers (e.g., Evans et al, 2009 ; Hagsand et al, 2022b ) and expert witnesses ( Kassin et al, 2001 ) have been found to believe that intoxication reduces witness credibility.…”