This month the House of Lords declined to grant a posthumous pardon for the crime of gross indecency for which he was convicted in 1952. Not only was he forced to undergo chemical castration, his security clearance was then withdrawn and he was unable to work for continue his work for GCHQ, Britain's intelligence agency. Turing committed suicide two year's later.
"A posthumous pardon was not considered appropriate as Alan Turing was properly convicted of what at the time was a criminal offence. He would have known that his offence was against the law and that he would be prosecuted."
Widespread Celebrations But No Pardon For Turing