The Escape of Frank Mitchell occurred on n Monday, 12 December 1966, and was involved springing the violent criminal Frank Mitchell from Dartmoor Prison.
Mitchell was sent to Dartmoor prison in 1962, and whilst there his behaviour improved. He kept budgerigars and was transferred to the honour party, a small group of trusties who were allowed to work outside the prison walls with minimal supervision. Mitchell was permitted to roam the moors and feed the wild ponies and even visited nearby pubs. On one occasion he caught a taxi to Okehampton to buy a budgerigar. The governor of the prison promised Mitchell that if he stayed out of trouble he would recommend to the Home Office that he be given a release date. Four years later, Mitchell was aggrieved that he had still not received one.
Mitchell befriended Ronnie Kray when they served a sentence together at Wandsworth prison in the 1950s. During Mitchell's trial for attempted murder, Ron hired a lawyer for him and paid for him to have a new suit fitted. Ron was keen on breaking Mitchell out of prison, thinking it would help him to publicise his grievance and earn a release date, as well as enhance the Krays' standing in the underworld. Reg Kray recalled that he was reluctant, but finally reasoned that "if nothing else it would stick two fingers up to the law". Reg visited Mitchell at Dartmoor in disguise and informed him of the plan. On 12 December 1966, while with a small work party on the moors, Mitchell asked the sole guard for permission to feed some nearby Dartmoor ponies. His request was granted, he walked over to a quiet road where a getaway car containing associates of the Krays – Albert Donoghue, "Mad" Teddy Smith and Billy Exley – was waiting for him, and they drove to London, where the Krays put him up in a flat in Barking Road, East Ham. It was over five hours before Mitchell was reported missing.
Mitchell's escape made national news, led to a political storm over the lax security around a man described in the press as "Britain's most violent convict", and was debated in the House of Commons. A large manhunt ensued, with 200 policemen, 100 Royal Marines and a Royal Air Force helicopter searching the moors. With the aid of Teddy Smith, Mitchell wrote to national newspapers and his plea to be granted a release date was printed in The Times and the Daily Mirror. However, Home Secretary Roy Jenkins was not willing to negotiate with an escaped felon and would not review his status until he was back in custody.