Can prior bad acts evidence rebut a witness mistake defense? State v. Richins Explained

The Utah Court of Appeals in State v. Richins addressed whether prior bad acts evidence could be admitted under Rule 404(b) to rebut a defendant’s claim that a witness was mistaken about what she observed.

Background and Facts

A fifteen-year-old girl observed her neighbor, Ronald Richins, in his yard with his hands near his genital area making what appeared to be masturbatory motions. While she admitted uncertainty about exactly what she saw, she reported the incident to her mother, who contacted police. Richins denied the allegations. The State sought to introduce evidence of four prior similar incidents where Richins had exposed himself to other women between 2007 and 2013.

Key Legal Issues

The central issue was whether the doctrine of chances permitted admission of prior bad acts evidence to rebut Richins’s defense that the victim was mistaken in what she observed. The court analyzed whether the evidence served a proper noncharacter purpose and satisfied the doctrine’s foundational requirements of materiality, similarity, independence, and frequency.

Court’s Analysis and Holding

The court affirmed admission of the evidence, reasoning that rebutting a false accusation defense constitutes a permissible noncharacter purpose under Rule 404(b). The court emphasized that whether the victim intentionally fabricated or was merely mistaken made no difference—both constitute false accusations. The prior acts were sufficiently similar, involving Richins exposing himself to women in public settings, and the frequency of such accusations against one individual exceeded normal probability. The court also found that any unfair prejudice was mitigated by limiting instructions and a sanitized stipulation that avoided detailed testimony about the prior incidents.

Practice Implications

This decision reinforces that the doctrine of chances can support admission of prior bad acts evidence even when the defense is mistake rather than intentional fabrication. Practitioners should carefully analyze whether the foundational requirements are met and consider negotiating stipulations to minimize prejudicial impact. The court’s footnote expressing concerns about the doctrine’s application to fabrication defenses suggests this area of law may continue evolving.