When jurors' moral judgments result in jury nullification: moral outrage at the law as a mediator of euthanasia attitudes on verdicts.

In a mock-trial study, jurors read evidence about a doctor who had killed a terminally ill patient at the patient's request. We tested whether instructing jurors about jury nullification (ie jurors' power to return a not-guilty verdict even when legal guilt is beyond doubt, often because the law would result in unjust convictions) would exacerbate the effect of pre-trial euthanasia attitudes on their verdicts - compared to standard, pattern jury instructions. We also hypothesized that anti-euthanasia pre-trial attitudes would result in moral outrage at the defendant and higher conviction rates, but pro-euthanasia attitudes would prompt feelings of moral outrage at the law and lower conviction rates. Moderated mediation analyses revealed that nullification instructions bolstered the effect of attitudes on verdicts by encouraging jurors to rely on their feelings of moral outrage toward the defendant. Jurors' moral outrage toward the law mediated the effect of attitudes on verdicts regardless of nullification instructions.