The Black Panther, so-called for his penchant for wearing a black balaclava, he was sentenced to life imprisonment in July 1976 for the murder of Lesley Whittle, two sub-postmasters and the husband of a sub postmistress. He was found not guilty of the attempted murders of sub postmistress Margaret "Peggy" Grayland and PC Tony White but guilty of the lesser alternative charges of inflicting grievous bodily harm on Mrs Grayland and possessing a shotgun with the intent of endangering life at Mansfield. A charge of attempting to murder a security guard named Gerald Smith who he shot six times while checking the Whittle ransom trail was left on file because of legal complications due to fact that Mr Smith died more than a year and a day after being shot. The trial judge recommended that Neilson receive a whole life tariff. After the verdicts, his counsel, Gilbert Gray QC, visited him in the cells below the court. He found his client in the corner of his cell curled up in a pre-natal position, totally broken and dejected, filled with immense remorse for Lesley Whittle and her family. He has since been confirmed on the Home Office's list of prisoners issued with whole life tariffs, as a succession of Home Secretaries have ruled that life should mean life for Neilson. The European Court of Human Rights legislation saw politicians lose that power in November 2002.
In 2008, Neilson applied to the High Court to have his minimum term reverted to 30 years. On 12 June 2008, however, Neilson's appeal was rejected, and he was told by the court that he will have to spend the rest of his life in prison. Now in his seventies, Neilson continues to serve his sentence at HM Prison Norwich and remains one of Britain's longest-serving prisoners.
