Suspects' decisions to waive or invoke their interrogation rights can have a considerable impact on their eventual legal fate. Although innocent and guilty suspects show differences in waiver rates, research has yet to examine whether innocent and guilty individuals' waiver decisions are differentially influenced by dispositional and situational factors. The current research examined the relationship among a dispositional factor (just world beliefs), a situational factor (social proof pressures—i.e., influencing others to believe that certain behaviors are normative) and innocent and guilty individuals' waiver decisions. Social proof pressures influenced the preinterrogation decisions of guilty individuals holding strong just world beliefs but not guilty individuals holding weak just world beliefs. However, social proof pressures influenced the preinterrogation decisions of innocent individuals holding weak just world beliefs but not innocent individuals holding strong just world beliefs. Results also indicated that strong just world beliefs are associated with attenuated stress responses to an accusation among innocent individuals but exacerbated stress responses among guilty individuals, thereby helping to explain why guilty and innocent individuals are differentially influenced by situational and dispositional factors. The theoretical and applied implications of these effects are discussed with an emphasis on the consequences of suspects' mindset during the preinterrogation decision-making process.