A defendant can plead insanity under which plea option?

The option that allows a defendant to plead insanity is the plea of "not guilty by reason of insanity." This legal standard provides that if a defendant was not aware of the nature of their actions at the time the crime was committed or could not distinguish right from wrong due to a severe mental disorder, they may be found not guilty based on their mental state. This plea serves to acknowledge that, while the accused may have committed the acts in question, they lacked the mental capacity to be held criminally responsible.

In contrast, pleading guilty indicates acceptance of responsibility for the crime without contesting the facts, which leaves no room for a mental health defense. The "not guilty" plea denies the charges but doesn’t address the defendant's mental state, nor does it provide an assertion of insanity. The "nolo contendere" plea means the defendant does not contest the charges but does not admit guilt, similarly precluding any claim of insanity. Therefore, "not guilty by reason of insanity" is the only plea that specifically incorporates the defendant's mental health status into the legal defense.