The subject of this disturbing programme is a vicious double killer, who attacked men, women and juveniles throughout his life of violent crime. Royston Jackson is one of just a tiny percentage of criminals who kill, serve time in prison for murder, then leave jail - only to take another life. As a result, he is now on a whole-of-life tariff and will die behind bars.With contributions from officers from both Norfolk Constabulary and the Metropolitan Police, this film looks at Jackson's despicable crimes, including two brutal murders - seventeen years apart. With remarkable access to scene-of-crime materials, and CCTV footage captured around the time of one of the murders, the full extent of Jackson's brutality and his vain efforts to escape justice, are revealed.The programme also looks at the difficulties that arise for police when victims of crime are offenders themselves – Jackson's second murder victim was an elderly paedophile and the indifference with which his death was greeted proved a major problem for the investigating officers.The film includes powerful testimony from several of the police officers central to the two murder investigations (including the Chief Inspector in Norfolk who brought Jackson to trial for murder for a second time), as well as a moving and candid interview with the daughter of one of Jackson's murder victims.The film doesn't just tell the story of what happened. With the help of leading experts including a renowned criminal psychologist, and eminent forensic scientist, Jackson's crimes are examined and dissected for both motives and methods. The result is a chilling account of one of Britain's most sinister killers, a man from whom no-one was safe.