Define: M’Naughten Rule

The M’Naughten Rule is a legal standard for determining criminal responsibility based on the defendant’s ability to understand the nature and consequences of their actions at the time of the offense.

Daniel M’Naughten was a Scottish woodcutter who, in 1843, attempted to assassinate British Prime Minister Robert Peel’s secretary, but mistakenly killed Peel’s secretary instead. The subsequent trial led to the establishment of the M’Naughten Rule.

Under the M’Naughten Rule, a defendant is considered legally insane if, at the time of the crime, they were so impaired by a mental illness or defect that they did not understand the nature or quality of their actions or that their actions were wrong.

The M’Naughten Rule provides a framework for determining criminal responsibility in cases where the defendant’s mental state is in question, serving as a key standard for insanity defences in many common law jurisdictions.

The M’Naughten Rule focuses primarily on cognitive impairment and lacks consideration for volitional impairment, which is addressed in other standards such as the Durham Rule or the Model Penal Code test.

Yes, some criticisms of the M’Naughten Rule include its narrow focus on cognitive impairment, potential for subjective interpretation by juries, and failure to account for mental disorders that may affect volitional control.

The M’Naughten Rule is primarily applied in common law jurisdictions, including England, Wales, and various states in the United States, although some jurisdictions have adopted alternative insanity standards.

Yes, some jurisdictions have modified or supplemented the M’Naughten Rule with additional criteria or tests for insanity, such as the irresistible impulse test or the substantial capacity test.

The burden of proof typically rests with the defendant to establish their insanity defence by a preponderance of the evidence, although the exact standard may vary by jurisdiction.