For lack of capacity due to mental disease to be used as an affirmative defense, the mental illness must be diagnosed.

For lack of capacity due to mental disease to be used as an affirmative defense, the mental illness must be diagnosed.

• A. True, diagnosis is required.
• B. Not required if the defendant had no prior offense.
• C. Diagnosis by any person is sufficient.
• D. Diagnosis is not relevant.

Answer: (A)

Lack of capacity due to mental disease as a defense relies on a diagnosed mental illness at the time of the offense. A formal diagnosis by a qualified professional provides the medical basis for claiming the defendant lacked the capacity to understand the act or to form the required intent. Without a diagnosis, the defense would rest on speculation rather than evidence, even if there is a history of mental illness. Diagnoses by laypersons aren’t typically sufficient, and factors like prior offenses don’t remove the need for a professional diagnosis.

Lack of capacity due to mental disease as a defense relies on a diagnosed mental illness at the time of the offense. A formal diagnosis by a qualified professional provides the medical basis for claiming the defendant lacked the capacity to understand the act or to form the required intent. Without a diagnosis, the defense would rest on speculation rather than evidence, even if there is a history of mental illness. Diagnoses by laypersons aren’t typically sufficient, and factors like prior offenses don’t remove the need for a professional diagnosis.