Alternative stories and the decision to prosecute: an applied approach against confirmation bias in criminal prosecution

Abstract

ABSTRACT In many legal systems, preliminary proceedings and the prosecutor’s charging decision predict the outcome of the trial, as reflected in high conviction rates. This charging decision is mostly based on the final police report, which is primarily aimed to substantiate the given suspicion and may lead to a preponderance of incriminating evidence. We investigated if a written statement by the defense (an alternative story) can balance out this information disparity and can alter the charging decision. Building on classical debiasing methods, the Story Model and narrative persuasion, we hypothesized that an alternative story reduces the likelihood of being charged, because the police report becomes less unique. Participants of three experiments (criminal-law students, N = 684) received either only the police report, or the police report plus an alternative story (vs. a statement merely claiming innocence) and were asked to make charging decisions. The presence of prior conviction evidence (PCE) was varied. Results show that 1) an alternative story reduces (and PCE increases) the likelihood of being charged, 2) a statement merely claiming innocence is less but still effective, and 3) PCE effects were small and inconsistent. Underlying mechanisms, implications for criminal procedural law, and applicability to adversarial systems are discussed.