Most criminal law defenses serve the criminal law’s goal of shielding blameless defendants from liability. Justification defenses, such as self- defense and law enforcement authority, exculpate on the ground that the defendant’s conduct, on balance, does not violate a societal norm. Excuse defenses, such as insanity and duress, exculpate on the ground that, while the defendant may well have violated a societal norm, it was done blamelessly. That is, it is the excusing conditions, not the defendant, that is to blame. In contrast, a third group of general defenses, which have been called “non-exculpatory defenses,” bar liability in instances where the defendant may have clearly violated a societal norm with full blameworthiness yet nonetheless is exempt from criminal liability because giving the exemption advances some societal interest independent of—and in conflict with—the criminal law’s goal of imposing deserved punishment in proportion to an offender’s blameworthiness. Non-exculpatory defenses openly sacrifice doing justice in order to promote the competing non-justice interest.

A wide variety of non-exculpatory defenses are commonly recognized, including, for example, statutes of limitation, executive and legislative immunities, double jeopardy, diplomatic immunity, and the doctrines of the legality principle. Each of these defenses let blameworthy offenders go free even for serious crimes because such restraint promotes or protects some non-desert societal interest. Our examination of the doctrines suggests, however, that those balances of competing interests are commonly misaligned. This occurs in some instances because societal circumstances have significantly changed since the initial formulation of the defense, without any corresponding revision of the doctrine. In other instances, there is reason to suspect that no thoughtful balancing of the competing interests ever took place, perhaps because at the time there was insufficient appreciation of the practical importance of doing justice and the societal costs of regular failures of justice.

In this article, we illustrate the problem by examining the three most commonly used non-exculpatory defenses: statutes of limitation, the double jeopardy rule, and the legality principle’s rule of strict construction. We acknowledge that each of these defenses was created to promote or protect an important societal interest. But we show that in each instance the societal circumstances have changed, altering the balance of competing interests, yet the formulation of the doctrines has not been adjusted accordingly. Our larger conclusion is that non-exculpatory defenses, based as they are upon a balance of competing societal interests, rather than principles of societal harm and personal blameworthiness, require constant re-examination and adjustment in ways that justification and excuse defenses do not.