M'Naghten's Case
- Case
- M'Naghten's Case
- Court
- House of Lords (United Kingdom)
- Year
- 1843
- Area
- Criminal law / Insanity defence
- Summary
After a killing committed under delusion, the House of Lords formulated the M'Naghten Rules — the long-standing common-law test for the defence of insanity.
- Holding
Laid down the insanity defence: an accused is excused if, through a disease of the mind, they did not know the nature and quality of the act, or did not know that it was wrong.