A FRESH appeal is being launched to prove that notorious teenage killer Luke Mitchell is innocent and should be freed from jail.

The campaign is being led by a Scots criminologist who has dedicated her life to fighting injustice and defending those she believes have been wrongfully convicted.

It will be the third appeal on behalf of Mitchell, who was 14 when he murdered his girlfriend Jodi Jones, also 14. Found guilty in February 2005 and sentenced to a minimum of 20 years, he has always maintained his innocence but failed to overturn his conviction in 2008.

Dr Sandra Lean is working with a legal team, compiling a fresh appeal. She has dedicated her career to the case, which happened in her hometown of Dalkeith in Midlothian 15 years ago.

The mother-of-two will also publish a book later this year which she claims will uncover failings in the original police investigation. She said: “This would be the biggest embarrassment possibly ever for the Scottish police.

“It was such a big case, the longest trial of a single accused in Scottish history. He was 14 years old when they first targeted him.

“I find this in all of the cases claiming wrongful conviction. The evidence before the jury is not all the evidence and never has been, never will be. It’s the evidence that supports the prosecution narrative.

“Now people find that really difficult to accept. Unless it can be tied specifically to something that the prosecution is alleging, it will not go before the jury.”

Jodi was stripped, tied up and stabbed to death in woods on June 30, 2003. Her body lay behind a wall running alongside a walkway known as the 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 face, breast and arms.

The final moments in her life became the focus of one of the biggest investigations ever conducted by Lothian and Borders Police. More than 200 police staff were involved in the inquiry, taking 3,150 statements from over 2,000 people.

During the subsequent high-profile trial at the High Court in Edinburgh, prosecutor Alan Turnbull QC described the tragedy as “the most gruesome killing of recent years”.

There were three main planks of evidence at the heart of the prosecution case, which was based entirely on circumstantial evidence.

The Crown suggested the evidence of the accused’s brother, Jodi’s family members and a passer-by were sufficient grounds on which to convict Mitchell, who lodged special defences of alibi and incrimination.

Mitchell, of Dalkeith, was convicted of the killing after the longest single-accused murder trial in Scots legal history. He was detained for life with a minimum of 20 years.

Mitchell has constantly protested his innocence. The murder weapon has never been recovered and there was no credible DNA evidence linking him to the killing.

Dr Lean, a mother of two daughters, had a quiet but content life, while running her new business - an alternative health centre in the town. This soon changed, when the area was rocked and divided by the murder.

After doubts that Mitchell was not the perpetrator of the crime, she began to investigate and became convinced the schoolboy had suffered a miscarriage of justice. She gained a PHD in criminal justice and has become a campaigner for those wrongfully convicted and currently works with the charity, the Miscarriages of Justice Organisation.

Dr Lean said: “I lived in the local area. It started with doubts about how quickly attention had focused on Luke, and some of the stories I was hearing seemed so ridiculous and small-town mentality– a lot of gossip.

“Then over time, more bits of pieces just seemed strange, and his mother Corrine put a note through the door of my workplace one day.

“It said, ‘I’ve heard what you’re saying about my son’s situation, can you help us?’ I knew nothing about the justice system or anything, but I agreed to meet her and Luke, and they started telling me about what had been going on and where some of the stories that were doing the rounds had come from.

“What convinced me he was innocent finally, was access to all of the case papers in 2009.”

Dr Lean claims she knew Mitchell was innocent the first time they met.

She added: “I was having a cup of coffee with Corrine and her mum Ruby, and this lad sort of ambled in, the head down. And then he just walked over, and he stuck his hand out and shook mine and said, ‘I’m Luke’. Very quiet, very, very polite. He looked – I thought – haunted. He looked me straight in the eye, I need to make that absolutely clear.”

In 2014, alongside the help of QC human rights lawyer, Maggie Scott – now a High Court Judge – the pair composed an appeal to present on Mitchell’s behalf to the Scottish Criminal Cases Review Commission (SCCRC) which was rejected.

She said: “This is not just about justice for Luke Mitchell, it’s about justice for Jodi as well, because I don’t believe she or her family have had justice and I never have.”

Jodi Jones’ family were approached for comment but they declined.