Sir William Lloyd Mars-Jones, MBE (4 September 1915 – 10 January 1999) was a Welsh barrister and High Court judge.
He served in the Royal Naval Volunteer Reserve, reaching the rank of lieutenant commander, and was appointed a Member of the Order of the British Empire (Military Division) in 1945.
[1] After the war, Mars-Jones joined the Wales and Chester circuit and practiced from the former chambers of Lord Justice Arthian Davies at 1 Farrar's Building.
In 1966, he assisted Attorney-General Sir Frederick Elwyn Jones in the prosecution of Ian Brady and Myra Hindley, the Moors murderers.
[4] The same year, he presided over the ABC trial: he described it as an "oppressive prosecution", which led to all charges under section 1 of the Official Secrets Act being dropped by the Attorney-General.