An investigation of implied Miranda waivers and Powell wording in a mock-crime study

Abstract

To guard against coerced self-incrimination, the Supreme Court of the United States outlined in Miranda v. Arizona (1966) what arresting officers must convey to custodial suspects for resulting statements to be admissible into evidence. During the ensuing decades, the Court has continued to grapple with the requisite wording and practical enforcement of these Constitutional rights. In Florida v. Powell (2010), the Court upheld the conviction of a defendant whose Miranda warning affirmed that before questioning he had the right to an attorney, but failed to specify that during questioning he had this right as well. In Berghuis v. Thompkins (2010), the Court ruled that the right to silence must be invoked explicitly, while valid Miranda waivers could be "implied" by a suspect's actions as well as words. The current study employed a mock crime design to assess the practical effects of these 2 rulings on waiver decisions. The wording change enabled by Powell had little effect on Miranda knowledge and reasoning. With regard to Thompkins, the type of waiver profoundly affected subsequent decisions: 13.7% exercised their rights following implied waivers versus 81.1% with explicit waivers. Importantly, the implied waiver condition produced much higher percentages of confessions (17.6% vs. 3.8%) and of admissions about incriminating information (29.4% vs. 9.4%).