A basic tenet of the American legal system is that to be justly punished for a crime, a defendant must be found to have actually committed the offense in question (actus reus) and to have had the mental capacity to have committed the act consciously, knowingly, and purposefully (mens rea).

The two major principles that guide insanity evaluations in the United States are the M’Naughten test and the American Law Institute (ALI) test; different states employ different standards. According to M’Naughten, in order to establish a defense on the grounds of insanity: “It must be clearly proved that, at the time of committing an act, the party accused was laboring under such a defect of reason, from disease of the mind, as to not know the nature and quality of the act he was doing, or if he did know it, that he did not know he was doing wrong.”

According to the ALI test: “A person is not responsible for criminal conduct if at the time of such conduct, as a result of mental disease or defect, he lacks substantial capacity either to appreciate the criminality (wrongfulness) of his conduct or to conform his conduct to the requirements of the law.”

What both standards share in common is a fairly strict set of exclusion criteria to invoke a defense of not guilty by reason of insanity (NGRI), or not guilty by reason of mental disease or defect. Both standards require the presence of a diagnosable mental disorder, but this is not in itself sufficient. The symptoms of that disorder must so impair the defendant’s mental functioning that he literally does not know what he is doing or doesn’t know right from wrong at the time of the offense (M’Naughten) or make it impossible for him to control his actions (ALI).

NGRI is raised as an affirmative defense in about one out of every hundred felony cases. In about half of those, the defendant is so obviously impaired that both prosecution and defense agree to adjudicate the case as NGRI without trial. In another quarter of those cases, the two sides come to an agreement during the trial, and so in only one-quarter of one percent of felony cases, do you get a Hollywood-like “battle of the experts.”

In Ohio, a person is “not guilty by reason of insanity” relative to a charge of an offense only if the person proves that at the time of the commission of the offense, the person did not know, as a result of a severe mental disease or defect, the wrongfulness of the person’s acts. (R.C. 2901.01(A)(14). Under Ohio law, the defense of NGRI is an affirmative defense that must be proved by the accused. The proper standard for determining in a criminal case whether a defendant has successfully raised an affirmative defense is to inquire as to whether the defendant has introduced sufficient evidence, which, if believed, would raise a question in the minds of reasonable men concerning the existence of such issue. In other words, the Defendant must prove by a preponderance of the evidence (think 51%) that the issue exists.

The bottom Line: I have experience both prosecuting and defending cases with NGRI issues. My office works with several forensic physiologist that are experience in diagnosing these issues and building a defense around them. If you or a loved one has gotten into legal difficulty as a result of an affliction with a severe mental health issue, I can help. Please do not hesitate to give me a call at my office or my mobile phone: 513-260-2099.