Morality Influences How People Apply the Ignorance of the Law Defense

In four empirical studies, we showed that laypeople apply the ignorance of the law defense differently depending on the perceived morality of the defendant’s course of conduct at the time of the illegal act. Moral and neutral defendants who pled ignorance of the law were afforded leniency, whereas immoral defendants were sentenced as though they were not ignorant, even when defendants in all three conditions violated identical laws. These findings suggest that laypeople adopt a just deserts approach to criminal law, which influences their responsiveness to a criminal defendant’s claim to be ignorant of the law. We discuss the implications of these findings for criminal law and argue that legal doctrine should reflect laypeople’s moral intuitions.