He has been in prison for 41 years for killing five members of his family. But if a phone call was made to the police by Bamber’s father on the night of the murders – as his team believes – one of the UK’s most notorious criminals could be exonerated

On 7 August 1985, five people were found dead at White House Farm in Essex, England: 28-year-old Sheila Caffell (known to her family as Bambi); her six-year-old twin sons, Daniel and Nicholas; and her 61-year-old adoptive parents, June and Nevill Bamber. All five had been shot with a rifle. Caffell’s 24-year-old brother, Jeremy Bamber, who was also adopted, had called to alert Essex police to a disturbance inside the farmhouse – he said his father had called to tell him – and had been outside with the police for four hours before the bodies were discovered. Caffell, who had recently been hospitalised with schizoaffective disorder and is said to have feared her children were going to be taken into foster care, was found with the rifle lying on her chest, pointing towards her neck. There were two gunshot wounds to her neck and chin and a bloodied Bible by her side.

The case was initially thought to be open and shut, a tragic murder-suicide committed by Caffell. But a month later, Bamber was arrested after relatives went to the police to voice their suspicions about him; his former girlfriend Julie Mugford then told police he had made a confession to her. The relatives went on to inherit from Nevill and June Bamber’s considerable estate after Bamber’s convictions. It was later discovered that Mugford had agreed to sell the story of their relationship to the News of the World for £25,000 if Bamber was convicted. Essex police and crown prosecutors had also agreed to drop charges against her for burglary, chequebook fraud and selling cannabis, because “prosecuting her could jeopardise her availability or credibility as a key witness” against Bamber.