In a criminal case, affirmative defenses require the defendant to prove them by

• A. Preponderance of the evidence
• B. Beyond a reasonable doubt
• C. Clear and convincing evidence
• D. A balance of probabilities

Answer: (A)

Affirmative defenses in criminal cases shift some persuasive burden to the defendant: the defense must prove the defense by a preponderance of the evidence. The prosecution still bears the burden to prove all elements of the crime beyond a reasonable doubt, but when the defendant asserts a defense such as insanity, duress, or self-defense, the defendant must demonstrate that the defense is more likely true than not. Preponderance means the evidence tips the scales just enough to show it is more likely than not that the defense applies. This standard is lower than beyond a reasonable doubt, reflecting that the issue is whether the defense, if true, would exonerate or lessen liability. While some contexts or jurisdictions may refer to other standards like clear and convincing, the typical rule for criminal affirmative defenses is preponderance of the evidence. A balance of probabilities is effectively the same notion, but the formal term used in criminal practice is preponderance of the evidence.