Nine-year-old Kayleigh Ward may have been streetwise. But her intuition could not save her from John O'Shaughnessy, who lured her to a river bank, then raped and murdered her, says Ian Burrell.

Kayleigh Ward had only popped out for a bag of chips. It was an errand for a woman who shared the hostel in Chester, Cheshire, where the nine- year-old had lived since her family had been evicted from their council house for rent arrears.

But it was on the way back from the chip shop last December that the child bumped into another resident of the hostel, John O'Shaughnessy. The chips were never delivered.

O'Shaughnessy, who today starts a life sentence for Kayleigh's murder, was described as a "drifter and shifter" who hung around the pubs. He had arrived at the hostel a month earlier with his pregnant girlfriend and her three children from a previous relationship.

When the 31-year-old suggested that Kayleigh took a walk with him by the river bank she went along. Her impoverished upbringing had forced her into a street life where she felt at home in the city centre, making friends with travellers and older children.

But Mold Crown Court was told during O'Shaughnessy's trial that at a remote spot by the River Dee, he fell upon the girl, barely four feet tall, and raped her. "I'll tell my mum, I'll tell my mum," she sobbed during the attack.

As she walked away in tears, O'Shaughnessy determined that she could not escape, and strangled her with his belt and her tights. He threw her body into the river. Then he took what John Rogers QC, for the prosecutor, described as "carefully calculated steps" to avoid detection. He told his girlfriend that his clothes had become muddy in a fight and returned his boots to the shop where he had bought them, saying they were marked.

When Kayleigh's mother became worried that her daughter had not returned home nearly a day later, O'Shaughnessy was one of the most zealous in the search party. He was interviewed several times by police and an attempted drug overdose fuelled suspicions.

But it was not until late February, two months after the murder, that he finally cracked. The body was found in the riverbed mud on 10 February and O'Shaughnessy made a midnight call to police to say: "I killed Kayleigh Ward."

Yesterday, Mr Justice Maurice Kay said O'Shaughnessy should serve a minimum of 30 years. "There is no crime more horrific than the murder of a child. What you did to Kayleigh Ward was unspeakable," he said. He called the killing "depraved, cruel and cowardly".

From the public gallery, Kayleigh's mother, Yvonne, screamed at O'Shaughnessy: "I hope you rot in hell." Outside the court she said: "Our lives will never be the same now that Kayleigh has gone forever, and with the knowledge of the terrible circumstances around her death."

Alex Carlile QC, for the defence, said that O'Shaughnessy had been "at risk" when very young but had been nothing more than "a drinker and a bit of a nuisance". He was the father of "several" children from other relationships and there was "never an inkling that he was a child-abuser" before Kayleigh was murdered.