Would Daniel M’Naughten Have Satisfied the M’Naughten Test for Insanity?

In February 1843, Daniel M’Naughten was tried in London for the murder of Edward Drummond, the private secretary to Prime Minister Robert Peel. M’Naughten was laboring under the delusion that Prime Minister Peel was part of a system that was persecuting him. Only by shooting Peel could he end the torment. Drummond became the victim of these delusions when M’Naughten mistook him for Peel. The trial of M’Naughten, the verdict of insanity, and the aftermath made legal history.

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Defense Counsel Can’t Present an Insanity Defense without the Defendant’s Consent

The court of appeals recently addressed an issue that has divided courts elsewhere: whether defense counsel may present an insanity defense without the defendant’s consent. The court ruled that defense counsel may not do so, stating that “because the decision of whether to plead not guilty by reason of insanity is part of the decision of what plea to enter, the right to make that decision is a substantial right belonging to the defendant.”

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Insanity, Clinical Standards, and Expert Testimony

In Moore v. Texas, which I discussed here, the Supreme Court of the United States held that courts must rely on current clinical standards when determining whether a defendant is intellectually disabled and so exempt from the death penalty. Must courts also defer to clinical standards when determining whether a defendant is insane and so exempt from criminal culpability? I don’t think so, for the reasons below.

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The American Psychiatric Association is about to release the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, commonly abbreviated DSM-V and pronounced “DSM five.” This is important to criminal lawyers because mental health issues are litigated in so many criminal cases, and the DSM is the generally accepted authority on mental health diagnoses. By … Read more