Which test indicates the defendant is not guilty if the act was committed with lack of substantial capacity to understand wrong or to conform conduct to law?

Which test indicates the defendant is not guilty if the act was committed with lack of substantial capacity to understand wrong or to conform conduct to law?

• A. M'Naghten test
• B. Irresistible impulse test
• C. Substantial capacity test
• D. Void for vagueness

Answer: (C)

The key idea is the Model Penal Code’s substantial capacity standard for insanity. This standard says a defendant isn’t criminally responsible if, due to a mental disease or defect, they lack substantial capacity to understand the nature or wrongfulness of their conduct or to conform their conduct to the law. The described situation—lacking substantial capacity to understand what’s wrong or to conform behavior to what the law requires—matches this standard exactly, because it covers both understanding the act’s wrongfulness and the ability to control or conform behavior. The M’Naghten test focuses on knowing right from wrong, which is narrower than the MPC’s dual focus on understanding and on conforming conduct. The Irresistible Impulse test centers on an inability to control actions, not necessarily on understanding wrong or conforming to the law. Void for vagueness concerns whether a statute is clear, not insanity standards.

The key idea is the Model Penal Code’s substantial capacity standard for insanity. This standard says a defendant isn’t criminally responsible if, due to a mental disease or defect, they lack substantial capacity to understand the nature or wrongfulness of their conduct or to conform their conduct to the law. The described situation—lacking substantial capacity to understand what’s wrong or to conform behavior to what the law requires—matches this standard exactly, because it covers both understanding the act’s wrongfulness and the ability to control or conform behavior. The M’Naghten test focuses on knowing right from wrong, which is narrower than the MPC’s dual focus on understanding and on conforming conduct. The Irresistible Impulse test centers on an inability to control actions, not necessarily on understanding wrong or conforming to the law. Void for vagueness concerns whether a statute is clear, not insanity standards.