Sir Richard David Muir (1857–1924) was a prosecutor for the British Crown, widely regarded as the greatest of his time; he played a prominent role in many of the most sensational trials of the early part of the 20th century, most notably that of Hawley Harvey Crippen.
Muir was born in Scotland, the son of Richard Muir, a shipping broker from Greenock. Although his father hoped him to be part of the family business, he travelled south to London, with thoughts of going on the stage. Instead, a brother persuaded him to become a barrister, which he funded himself by working as a Parliamentary reporter for The Times. After entering chambers he starting working for the Crown as a prosecutor. While he never "took silk" (that is, appointed as a King's Counsel) he represented the Crown in every trial of note in the Old Bailey from 1901 until his death.
Muir was known to be hard working with little need for conviviality. He usually spent half the night preparing for his cases, making notations on small cards with coloured pencils — one colour for examination in chief, one colour for cross examination, and so on. So ubiquitous were those cards that came to be known as Muir's "playing cards". He was rightfully feared by his clerks and officers from Scotland Yard who gathered his evidence from him, for he asked the same thoroughness from them as from himself. He depended a lot from physical evidence, while giving eyewitness testimony little credence, except if it would bolster existing, more concrete evidence.
Such was his reputation for thoroughness and diligence that when Dr. Crippen learned that his prosecutor was Richard Muir, he remarked, "I wish it had been anybody else... I fear the worst." Muir's cross examination of Dr.Crippen became standard reading material for Bar students in England and Wales and was used to illustrate advocacy skills in general.
Because he was never appointed as King's Counsel, Muir was not eligible to become a judge of the King's Bench Division. He was, however, eligible to become a Recorder. Although he was passed over the position of Recorder of London, he was appointed as Recorder of Colchester by the then Home Secretary, Winston Churchill, in particular because of his work in the Edward Mylius libel case. He was a Master of the Bench of the Middle Temple and was conferred his knighthood in 1918.
Sir Richard married Mary Beatrice Leycester and they had a son who also became a barrister, but who died on 4 November 1918 of influenza while on active service in the Army. His son's death left him heartbroken. Muir himself died suddenly in January 1924 in his house in Camden House Court, Kensington and he was interred in West Norwood Cemetery after a service at St Mary Abbots, Kensington.
- Felstead, Sidney Theodore. Famous Criminals and their Trials: Intimate Revelations compiled from the papers of Sir Richard Muir. New York: George H. Doran Company, 1926.
- Obituary, Death Of Sir R. Muir, The Times, 15 January 1924