MBE Practice Test 2026 – Complete Exam Prep Tool

Evaluating the insanity defense focuses on the defendant’s mental capacity at the time of the offense: could they understand that what they did was wrong, or could they conform their conduct to the law? Courts use different tests, depending on jurisdiction, such as M’Naghten, which centers on knowing right from wrong, or the Model Penal Code’s substantial capacity test, which looks at the ability to appreciate criminality or to conform conduct to the law. Some jurisdictions also consider a volitional element (like the ability to control impulses), but the common thread is assessing whether mental impairment affected the legal state of mind, not merely whether the person was mentally ill in a general sense. It’s not about psychosis alone or about traits like age, intelligence, or education; those factors don’t determine insanity—the legal standards do.