Joe Geeling, 11, was beaten, repeatedly stabbed and dumped in a park in Bury, Greater Manchester, on 1 March 2006.

Michael Hamer, who was 14 at the time of the attack, pleaded guilty to murder at the start of his trial at Manchester Crown Court.

Hamer was told that he would serve a minimum of 12 years before being eligible for parole.

On 1 March a massive search was launched for Joe, a cystic fibrosis sufferer, after he failed to return home from school.

His body was found hidden under debris in a gulley in Whitehead Park the next day.

Mr Justice McCombe said Joe had done absolutely nothing to encourage Hamer's sexual advance, the rejection of which triggered the attack.

Imposing a minimum tariff of 12 years, the judge said doctors had found that Hamer was suffering from an "adjustment disorder" at the time of the murder.

He also said the killing itself was not thought of in advance but triggered by Joe's rejection of the defendant's sexual advance.

Earlier Alistair Webster QC outlined the prosecution's case against Michael Hamer.

He told the court Joe was reported missing by his mother at 1724 GMT.

'Lured to house'

Mr Webster said Hamer had written Joe a letter - purportedly from the deputy head at his school - to lure him to his house.

The court was told a second letter found at Hamer's home showed a clear sexual interest in Joe by Hamer. A total of four drafts of the letter were found by police.

Hamer claimed Joe came to his house to charge his mobile phone, but this explanation did not "stand up to examination", Mr Webster said.

Joe was beaten repeatedly with a frying pan, which left him with multiple bruises to the head and a fractured eye socket, the court heard.

Hamer told police he had got the frying pan because Joe had been looking at a photograph of his dead step-brother, which he refused to put down.

But Mr Webster said Hamer's account "lacked credibility" because no photo was found.

Hamer then went and took two knives from the kitchen and stabbed Joe 16 times, puncturing his windpipe in two places and cutting a major artery.

Mr Webster told the court Joe was the victim of a "sustained and savage attack".

Although there was no evidence to indicate a sexual assault the evidence did not exclude one, he said.

After the attack, Hamer dragged Joe's body downstairs, put it in a wheelie bin and took the bin to Whitehead Park, where he hid it.

'A wind-up'

When he returned to the house he began cleaning Joe's blood and told his mother the stains on the carpet were caused by a leaking red pen.

Later, he admitted his responsibility for the death but told police he had set up the meeting with Joe as "a wind-up" - so Joe would go to meet him but no-one would be there.

But David Steer QC, mitigating for the defendant, said Hamer killed Joe after an "adolescent sexual approach" was rejected.

Mr Steer described Hamer as "maladapted" - an isolated and psychologically flawed teenager.

Hamer felt rejected and isolated, which was exacerbated because he never knew his older half-brother, Mark, who died from cancer and did not have much contact with his father. He had also been bullied at school.

"This previous background to the commission of the offence leads both psychologists to conclude he was a young man suffering from a abnormality of mind in the form of an adjustment disorder," Mr Steer added.

Hamer told psychologists he lured Joe to his home to scare him and make the victim feel what it was like to be "isolated and scared" as he was when he was bullied.

But Mr Steer told the court: "We submit he simply did not feel able to admit that his motive was a sexual one. He found it easier to give these other accounts."

He said Hamer had only admitted the real reason for the murder in the last few days.

"He made a sexual advance towards Joe who responded to him as 'gay' and threatened to tell others about what he had tried to do," Mr Steer told the court.

"He then tragically responded in the way he did."

Mr Steer said: "I've been asked specifically by him and his mother to express their sorrow and deep regret for what happened in this case."

Eddie Robinson, headteacher of St Gabriel's Roman Catholic School in Bury, where Joe and his killer were pupils, said the school did all it could to ensure the care and safety of all its pupils.

"I'm confident that our policies and procedures are robust and any incidents of bullying are resolved quickly and effectively.

He added: "The outcome of today's proceedings should allow the school to begin to begin to work towards closure, and attempt to get back to some degree of normality."

Profile of a schoolboy killer

by Mark McGregor - BBC News, Manchester

Monday, 16 October 2006