Giving her mother a brief kiss goodbye, Jodi Jones bounded out of her house into a warm June evening.

Nothing seemed out of the ordinary when the 14-year-old set off to visit her boyfriend, Luke Mitchell, who lived about a mile away.

But that day in 2003 turned out to be the last time Judith Jones would see the daughter she called her "little mentor".

The journey from Easthouses to the Newbattle areas of Dalkeith, Midlothian, should have taken minutes - but Jodi never arrived.

More than five hours later, her bound and naked body was found behind a wall off the secluded Roan's Dyke path.

A hole had been cut in her windpipe and the main artery in her neck was severed virtually all the way through.

The schoolgirl had multiple injuries to her head, and wounds to her ear and the tissue around her eye. Deep cuts to her left breast and right arm were also inflicted after death.

Only the troubled mind of her killer knows the full horror she endured and the answer to the question: "Why was Jodi killed?"

The final moments in her short life became the focus of one of the biggest investigations conducted by Lothian and Borders Police.

A total of 220 police staff were involved in the inquiry, taking 3150 statements from more than 2000 people.

Detectives searched Mitchell's home on July 4, four days after Jodi's body was found, and took a number of items away for examination.

More than 20 bottles of urine, a Marilyn Manson CD and DVD and a calendar featuring the goth musician were among the items seized.

On August 14, Mitchell was detained for questioning but was released later without charge.

Despite a lack of evidence to arrest him, the teenager found himself ostracised by the local community.

He was unable to return to St David's Roman Catholic High School, where Jodi had also been a pupil, for the start of the new term due to fears for his safety.

And Jodi's family banned him from attending her funeral at Gorebridge Parish Church on September 3.

But on the same day, as hundreds of mourners gathered to pay their last respects to the schoolgirl, Mitchell broke his silence over her death in a TV interview, in which he insisted he was not the killer.

It was on April 14, 2004, that the teenager was arrested and charged. What followed was the longest trial of a single accused person in Scotland.

The distressing two-month case left an indelible mark on all who sat through it. The jury heard much circumstantial evidence, but there was no single piece of evidence that unequivocally pointed the finger at Mitchell.

Evidence emerged about his fascination with knives, his enjoyment of cannabis and the fact he was two-timing Jodi with a girl who was "almost identical" to her.

The prosecution attempted to paint the picture that American "shock rocker" Manson's work was connected to Jodi's killing.

The trial also heard evidence about his school books being daubed with satanic slogans. But the murder weapon has never been recovered and there was no credible DNA evidence linking Mitchell to the killing.

In his closing speech, Alan Turnbull QC narrowed the prosecution case down to three key pieces of evidence. He argued the evidence of the accused's brother, Jodi's family members and a passer-by were sufficient grounds on which to convict Mitchell.