Factors affecting false guilty pleas in a mock plea bargaining scenario

Abstract

Purpose We sought to investigate key factors that legal scholars believe are contributing to false guilty pleas. Methods Undergraduates playing the role of an innocent defendant in a plea bargaining scenario (N = 382) were randomly assigned to condition in a 2 (trial penalty: mandatory minimum of 10 years, judicial discretion of 4–6 years) × 3 (likelihood of conviction: 10%, 50%, 90%), × 2 (attorney recommendation: take the plea deal, use best judgement) between‐subjects design – false guilty pleas (2 years in prison) were the primary dependent variable. Results Participants faced with a mandatory minimum were more likely to falsely plead guilty, and this effect was mediated by perceptions that life would be more difficult serving the sentence associated with losing at trial compared to that of the plea. Participants given a 90% likelihood of conviction at trial were more likely to falsely plead guilty than those in the 50% and 10% conditions, and this effect was mediated by perceptions of case strength. Finally, female participants (via increased perceptions of case strength) were more likely to falsely plead guilty than male participants. Contrary to our predictions, attorney recommendation did not impact false guilty pleas, perhaps due to the absence of a proper social influence component to the manipulation. Conclusions Overall, the findings provide evidence supporting the apparent causal mechanisms underlying the ‘innocence problem’ in plea bargaining, and we discuss future directions for plea bargaining research pertaining to both research questions and methodology.

Disentangling the effects of plea discount and potential trial sentence on decisions to plead guilty

“…While it is in line with existing research (and is intuitive) that plea acceptance will go up with increasing discount (Dervan, ; Dervan & Edkins, ), the effect of PTS severity requires some unpacking. Much legal and psycho‐legal commentary on the effect of threatened trial sentences contemplates the potential for coercion with increasing threat of punishment (Dervan & Edkins, ; McAllister & Bregman, ; Zimmerman & Hunter, ). It is not unreasonable to think that threat of extreme trial sentences may lead to risk‐averse behaviour, and conclusions based on existing empirical research have generally supported the notion that plea acceptance increases with increasing PTS (Gregory et al ., , Exp.…”

“…It is not unreasonable to think that threat of extreme trial sentences may lead to risk‐averse behaviour, and conclusions based on existing empirical research have generally supported the notion that plea acceptance increases with increasing PTS (Gregory et al ., , Exp. 1; Zimmerman & Hunter, ; Dervan & Edkins, ). However, as noted earlier, in most prior studies, severe trial sentences have been inadvertently paired with large discounts and smaller, less severe sentences with smaller discounts (Gregory et al ., , Exp.…”

“…1; Tor, Gazal‐Ayal, & Garcia, ). While innocent mock defendants are substantially less likely to plead guilty – even when it may be in their best interest to do so (a phenomenon that has been dubbed the Innocence Effect ; Gazal‐Ayal & Tor, ) – false guilty pleas in the laboratory have been observed to increase when the plea sentence is sharply discounted from the potential trial sentence (Bordens, ) and as potential trial sentence becomes more severe relative to the plea sentence (Zimmerman & Hunter, ).…”

“…These data have generally led to the (reasonable) conclusion that as the number and severity of charges increases, a defendant's perception that conviction at trial is certain and that the loss would be substantial also increases, thus compelling him or her to plead (Dripp, ; Gregory et al ., , Exp. 1; Zimmerman & Hunter, ). But, laboratory research on the effect of sentence differentials on plea decisions is limited to a handful of studies.…”

“…Moreover, most studies that have examined this effect have held the plea sentence constant while manipulating the magnitude of the potential trial sentence (e.g., Dervan & Edkins, ; Gregory et al ., , Exp. 1; Zimmerman & Hunter, ), confounding the effects of potential trial sentence with plea discount. For example, Zimmerman and Hunter () randomly assigned participants to low (2 to 6 years) and high (10 or more years) trial sentence conditions while offering a 2‐year sentence in exchange for a guilty plea in both conditions.…”