Darren Cornelius left Kitrina McKenzie, now 17, for dead outside the Fountainpark leisure complex after stabbing her eight times, including through the neck.

Despite being detained in a secure unit for that attack in 2000, when Cornelius was aged just 11, he has since been freed to attack again.

Yesterday, a judge added nearly four years to the minimum time he must spend behind bars after the 18-year-old admitted slashing a fellow prisoner in Saughton.

He was already locked up for carrying out a horrific knife attack on a stranger who crossed his path in the street in Bruntsfield.

Today, Kitrina, who spent a week in hospital and several more months recovering physically from the attack, said no prison sentence was enough for him.

"I want him to be taken to the US and given the death penalty. That's what he deserves, he can't help himself," she said.

"If he ever gets out he'll do it again. It's amazing he hasn't killed anyone yet, it's not for the lack of trying anyway. If he was to die I think I'd throw a party.

"If he'd just stabbed me and nothing else it wouldn't make him that different from others, but he's done so much stuff."

Kitrina also recalled how Cornelius – who was said to have a mental age of eight when he attacked her – had apologised for trying to kill her after the two came face-to-face at a tae kwon do class.

"After it all happened, I kept seeing him all the time. I'm not scared of him though. Maybe I was a bit at first, but not any more.

"I remember I was going to a tae kwon do class three years after the attack and I saw him there, that was one of the first times after it happened.

"I wanted to turn back and go home, but I was with my gran and she said I should go anyway.

"I ignored him, but I was standing with a friend who he knew too, so he came over and I suppose he had to say something so he just went, 'sorry eh, shouldn't have done it'. I just walked away and didn't say anything, I didn't want anything to do with him."

Cornelius is the only Scots teenager who is the subject of an indefinite detention order. As a result of his latest offence, he must serve a minimum of eight years before he can be considered for release. However, he cannot be released until he is judged no longer a threat to the public.

He attacked Kitrina, when she was just eight, after dragging her from the street where she was playing outside her grandmother's house in Longstone.

While Kitrina's memory of the attack is sketchy, it is still all too fresh in the mind of her mother, Rhona, 37.

"She died in the back of the ambulance and they had to bring her back, that's how bad it was," she said.

"I know they say he's in there indefinitely but it is Scotland, isn't it? Of course he's going to get out. He knows how to act like an angel when he wants to, he knows exactly what he's doing.

"I'm so proud of Kitrina the way she has come back from this."

LIFE AND CRIMES OF TEENAGER FROM HELL
October 2000: His first serious attack, stabbing nine-year-old girl Kitrina McKenzie eight times, leaving her within inches of death

May 2001: Released after serving eight months and returned to the streets of west Edinburgh

July 2002: Back in secure accommodation after crashing his mum's car into three parked cars and a wall, as well as being charged with assault on a 12-year-old boy

January 2005: At age of 15, faced five sex charges against two girls, but the case collapsed

March 2007: Scarred Daniel Sweeney for life after an unprovoked attack in Bruntsfield

July 2007: Slashed fellow prisoner Ryan Gandy's face in Saughton Prison over a game of table tennis

May 2008: Given lifelong restriction, meaning he could spend his whole life behind bars, and will always require supervision from the authorities

July 2008: Had sentencing deferred to High Court for a stiffer penalty on the Gandy slashing

August 2008: Had extra four years added to previous sentence, keeping him inside for at least eight years