When the jury were informed of his previous conviction, and his release as a “cured” mental patient only months before the crimes took place, they recommended an urgent review of the law regarding the public sale of poisons.The Home Secretary also announced an immediate review of the control, treatment, assessment and release of mentally unstable prisoners, despite the fact that Young had been regarded as legally sane during his trial. The Aarvold Report, published in January 1973, led to the reform of the way these prisoners were monitored upon release, and resulted in the creation of the Advisory Board for Restricted Patients.When asked whether he felt any remorse over his sadistic killings, he is said to have replied: “What I feel is the emptiness of my soul.”Young was incarcerated at the maximum-security Parkhurst prison, on the Isle of Wight, the home of Britain’s most serious criminals, usually reserved for those with severe mental conditions. Here he befriended Moors Murderer, Ian Brady, who became infatuated with the 24-year-old Young, although the attraction was not reciprocated. Brady described Young as genuinely asexual, excited only by power, clinical experimentation, observation and death. They spent considerable time together, playing chess and bonding over their fascination with Nazi Germany; Young regularly sported a Hitler moustache.Young was thrilled when a waxwork of himself was added to the Madame Tussaud’s ‘Chamber of Horrors’, alongside his boyhood hero, Dr. Crippen.Young died in his cell at Parkhurst on 1 August 1990, aged 42. The official cause of death was heart failure, although there remains conjecture that fellow inmates, who, with the exception of Brady, were always extremely wary of Young, may have poisoned him or, alternately, that he grew tired of prison life and poisoned himself, in one final gesture of control.Young’s worldwide notoriety brought the effectiveness of thallium as a deadly poison into focus for the first time: it was used extensively as a coating on US missiles fired during the first Gulf War, to devastating effect.In 1995, a black comedy about Young’s life, entitled ‘The Young Poisoner's Handbook’ was released in cinemas.In November 2005, a 16-year old Japanese schoolgirl was arrested for poisoning her mother with thallium. She claimed to be fascinated by Young, having seen the 1995 film, and kept an online blog, similar to Young’s diary, recording dosage and reactions.