What significant event occurred in the case of R v. McNaghten that led to changes in legal standards for insanity defenses?

In the case of R v. McNaghten, the significant event that led to changes in legal standards for insanity defenses was indeed the public outrage that followed the acquittal of the accused. McNaghten was found not guilty of murder on the basis of insanity, as it was determined that he was unable to understand the nature of his actions or to know that what he was doing was wrong due to a mental illness. This acquittal sparked considerable controversy and concern among the public, as many felt that the criminal justice system had failed to hold someone accountable for a serious crime.

In response to the public outcry and the perceived need for a more comprehensive approach to the insanity defense, the House of Lords introduced the McNaghten Rules. These rules established the legal standards for determining whether a defendant could be considered insane at the time of committing a crime, focusing on whether the individual understood the nature of their actions or knew that those actions were wrong. As a result, the case not only had a profound impact on the legal framework surrounding insanity defenses but also highlighted the interplay between legal standards and public perception in the criminal justice system.