The Death of Alan Turing

Alan Turing was the British mathematician and logician who laid theoretical foundations for modern computing, broke Nazi Germany's Enigma codes at Bletchley Park during World War II, and pioneered the field of artificial intelligence. In 1952, Turing was prosecuted under British law for "gross indecency" after reporting a burglary to police, which led to the discovery of his relationship with another man. He was convicted, subjected to forced chemical castration as an alternative to imprisonment, and stripped of his security clearance. On June 7, 1954, he was found dead at his home in Wilmslow, Cheshire, beside a half-eaten apple that tested positive for cyanide.

The official inquest verdict was suicide by cyanide poisoning. The commonly accepted narrative was that Turing had bitten into an apple he had laced with cyanide — a death sometimes romantically linked to the Snow White fairy tale, which he reportedly loved. However, the apple was never tested at the inquest, and his mother and others close to him maintained until their deaths that his death was accidental — that he had been conducting chemistry experiments in his home and may have inhaled cyanide fumes or accidentally contaminated food.

A third theory, advanced periodically, suggests assassination by British intelligence services, who had recently stripped him of his clearance and might have considered him a security liability due to his homosexuality during the height of the Cold War. This theory has never been substantiated with evidence. The lack of a thorough investigation at the time — his death was treated as straightforward rather than suspicious — means the exact circumstances will likely never be resolved.

In 2009, British Prime Minister Gordon Brown issued a formal apology for the persecution Turing endured. In 2013, Queen Elizabeth II granted him a posthumous royal pardon. His face now appears on the British £50 banknote. The circumstances of his death remain officially recorded as suicide, though the question of whether that verdict is correct — and whether one of the greatest minds of the twentieth century was driven to self-destruction or murdered by the state he had helped save — continues to be debated.