Diminished Capacity

Definition

Diminished capacity is often included as part of a “mens rea” defense where the defense argues for a lesser degree of culpability (e.g., manslaughter instead of first-degree murder) due to decreased intent. Although they both involve an assessment of a defendant’s mental state at the time of the commission of a crime, a diminished capacity defense is distinct from the insanity defense. In an insanity defense, the defense argues that the defendant lacks the mental capacity “as a result of mental disease or defect” to: appreciate the criminality (e.g., wrongfulness) of the act and to conform his/her conduct to the requirements of the law. In a diminished capacity defense, the defense argues that the defendant had a decreased level of intent to commit the act as a result of several possible factors including: drug or alcohol intoxication, medication use, and neurological conditions (Melton, Petrila, Poythress, & Slobogin, 2007). The most extreme variant of the diminished...