A psychopathic former soldier will die behind bars for the appallingly savage and sadistic murder of a “bright, lively and happy” four-year-old boy.

Anwar (Danny) Rosser was sentenced to a whole life term of imprisonment at Bradford Crown Court yesterday afternoon after a judge branded him “an exceptionally dangerous man” who could kill another child.

Rosser, 33, pleaded guilty to the murder of twin boy Riley Turner who was strangled and stabbed repeatedly while he slept in his bed at the family home in the early hours of January 20 last year.

Riley’s family and their friends erupted in a mixture of relief and rage when Mr Justice Coulson told Rosser: “You must go to prison for life.”

The packed public gallery, including Riley’s mother, grandparents and other close relatives, had behaved with great dignity earlier in the case, crying quietly as the terrible details of the little boy’s murder were outlined.

Police officers had escorted some family members from court at one stage to spare them the full details of what happened to Riley.

But when sentence was passed, people stood up and hurled abuse at Rosser.

The public gallery was cleared and the judge continued to address Rosser saying: “You will remain in prison for the rest of your natural life.”

Rosser, a part-time chef, was allowed to sleep on the sofa when he turned up drunk at the home of Riley’s mother Sharon Smith and his stepfather Guy Earwaker in Harewood Road, Bracken Bank, Keighley.

Riley and his identical twin brother, Mackenzie, slept in separate bedrooms, and his parents and baby brother, Tyler, shared another room.

The couple took pity on Rosser, who lived over the road, because he said people he owed money to were waiting outside his flat that night.

While the family slept, Rosser went upstairs with four knives and murdered Riley.

The youngster was strangled and had suffered multiple stab and incised wounds. Mr Earwaker saw Riley’s bedroom light on and found his bloodstained body.

He bravely chased Rosser down the street before carrying the dead child in his arms to a neighbour’s house.

Rosser was discovered in a caravan on a smallholding. There were blood smears on the caravan and the snow surrounding it.

He said: “I have ruined my life” and later told the police he suffered from Post Traumatic Stress Disorder, which was a lie.

He spent four years in the Army serving with the Royal Artillery but never saw active service.

Yesterday Rosser, wearing a black jacket, blue shirt and blue trousers, sat in a secure dock flanked by five prison officers.

His hands were clasped and his head bowed as Paul Greaney QC, barrister for the Crown, said: “By any standard, the circumstances of the killing were appalling, involving a savage level of violence.”

Mr Justice Coulson said Riley’s murder was a gross breach of the trust of Riley’s mother and stepfather. “They had taken pity on you and allowed you to stay, trusting you to share their home with their children.

“Your response was the savage murder of their son as he slept in his own bed,” he told Rosser.