John M. K. in R v. M'Naghten

In the context of the legal case R v. M'Naghten (1843), the term "John M. K." does not directly correspond to a specific legal concept within that case. Instead, M'Naghten established the M'Naghten Rule, which defines the legal standard for insanity in criminal law. According to this rule, a defendant may be excused from liability if, at the time of the crime, they were suffering from a severe mental disorder that prevented them from understanding the nature of their actions or knowing that their actions were wrong. This standard is crucial in determining competency in criminal cases.