Dissertations, Theses, and Capstone Projects

Date of Degree


Document Type


Degree Name





Margaret Bull Kovera

Committee Members

Saul Kassin

Lora Levett

Steve Penrod

Steve Young

Subject Categories

Legal Studies | Social and Behavioral Sciences | Social Psychology


Alford pleas, legal decision making, plea bargaining, voluntariness


Defendants often plead guilty in exchange for reduced punishments. Some argue that these reduced punishments are necessary for the functioning of the criminal justice system, whereas others argue that they are inherently coercive because they place a burden on the exercise of constitutional rights. This potential coercion is of concern because the constitution requires valid guilty pleas to be made by defendants voluntarily. However, “voluntary” is an elusive construct of which courts, scholars, and laypeople have differing definitions. Although limited research has focused specifically on perceptions of voluntary pleas, decades of research have shown that individuals generally perceive decisions more favorably when the process that led to those decisions is fair (Thibaut & Walker, 1978) and when the outcomes of those decisions are more rather than less desirable (Deutsch, 1975). In the present studies, I applied these frameworks to examine how different plea outcomes—including the size, type, and framing of the plea offer—affect perceptions of voluntariness for both those who make decisions and those who observe others make decisions.

I conducted two studies using participants from Qualtrics Research Panels. In Study 1, 1,518 participants played the role of a defendant in a simulated plea decision-making process. In Study 2, 949 participants played the role of an observer to a simulated plea decision-making process. In both studies, participants read about the basic facts of the case, reviewed an animated recreation of the incident, and viewed video-recorded materials in which a defense attorney counseled the defendant on their case. The defense attorney explained that the prosecutor was offering a plea deal that varied in size (50% sentence reduction, 90% sentence reduction), type (traditional guilty plea, Alford plea), and frame (plea discount, trial penalty). Participants then rated the voluntariness of the plea decision-making process by responding to twenty items on seven-point scales that had high internal reliability in both studies (Cronbach’s αs > .89).

Plea outcomes affected both defendants’ and observers’ decisions and perceptions, albeit in different ways. In Study 1, defendants were more likely to plead guilty when they were guilty rather than when they were innocent, when they were offered an Alford plea rather than a traditional guilty plea, and when the plea offer was larger (i.e., a 90% sentence reduction) rather than smaller (i.e., a 50% sentence reduction). Many of these variables also affected their perceptions of voluntariness. For example, innocent defendants rated the plea decision-making process as less voluntary than did guilty defendants. They also were more attuned to variations in plea outcomes. Specifically, innocent defendants rated the plea decision-making process as less voluntary when they were offered a smaller plea (compared to a larger plea) and when they were offered an Alford plea that did not require them to admit they were guilty of the accusation (compared to a traditional guilty plea). In Study 2, rather than the actual content of the plea offer, observers’ perceptions of voluntariness were affected by the way in which it was communicated by the defense attorney. Specifically, observers rated the plea decision-making process as less voluntary when the defense attorney explained that the defendant would receive a harsher sentence for taking their chances at trial compared to a more lenient sentence for accepting the plea offer.

Taken together, the results of these studies demonstrate the power that both prosecutors and defense attorneys have over plea decisions and perceptions of the plea decision-making process for both defendants and observers. Some scholars have raised concern that offering defendants any lesser sentence is an inherently coercive practice in that it is effectively bribing them to waive their constitutional rights. These studies emphasize the need to further explore the effects of plea outcomes on defendants’ plea decisions and their perceptions of those plea decision-making processes. There may, in fact, be a point at which a plea offer becomes so enticing that defendants feel as though they are being given an offer that they cannot refuse. The exact point at which that occurs, however, may differ based on myriad factors—including the defendants’ guilt, their prior experience with the criminal justice system, and their trust in their own attorney. Future research should focus on illuminating these factors to work toward understanding defendants’ experiences as they make these consequential decisions.