The heartbroken family of 12-year-old Stephen Hughes said they are reliving the pain of his death after news that his killer plans to appeal his 15-year sentence.
Stephen was killed when his makeshift den was set alight in Rossfield Avenue, Tallaght, on September 1, 2001.
Elizabeth Hughes (45) said that they will never get over the brutal killing.
Ms Hughes said that learning of her son's killer Dermot Griffin's bid to have his sentence cut was opening new wounds.
"We can't believe this is happening," she said.
"He's just putting the knife back into my heart again and twisting it.
"Griffin has never shown any remorse for what he did to my son and he should just accept his punishment for claiming the life of an innocent child.
"We fought for 13 years to get justice and when the trial was over we only started to grieve properly for Stephen.
"To think this monster could have his sentence reduced just makes me sick."
Ms Hughes said that she doesn't want Stephen's great grandmother Mary McKeon to learn of Griffin's new bid.
"My grandmum is 93 and I'm afraid to tell her about this because she will be completely devastated," she told The Sun.
Griffin (54), of Ballyfermot Road, had 39 previous convictions, including assault causing harm, burglary and robbery. He is currently serving time in Mountjoy Prison.
Griffin was found guilty of Stephen's manslaughter, after he set fire to the den at Rossfield Avenue in Tallaght on September 1, 2001.
Stephen was sleeping in the den with his pal Daryl Hall when Griffin set it ablaze.
Hall, who was 14 at the time, described in court how he scrambled out of the burning hut and tried to rescue his friend Stephen.
"I thought he was behind me. When I got on the wall, standing on the wall, I jumped back down. I tried to lift up the door, I heard him coughing," he said.
But Daryl was unable to lift the hut open again and got back up on the wall and started screaming for help, but it was too late.
The main evidence in the case came from three witnesses who placed Griffin at the scene.
But it took a dramatic change in evidence in 2012 when witness Tracey Deegan came forward and told gardai she had lied in 2001 to cover for Griffin.
"The dogs in the street knew he did it, but it took Tracey Deegan to change her evidence," Liz said.
Liz said that she was tormented that her son's killer was walking free.
"I would see Griffin nearly every day. I could be standing beside him in the shops," Liz previously told the Herald.
"I did confront him once but he just walked away, but that just made me stronger - more determined that I could not give up."
Liz said she now gives Griffin no thought at all.
"I thought long and hard about him for 13 years, wondering how we would ever see justice. Now that we have that I don't give him a second thought," she explained.
"I didn't realise it at the time but I carried a cross in my heart for all those years.
"You think you are getting along from day-to-day and coping, but it's only when you get that justice, and get that closure, and you can let go, that you realise just how heavy the pain was," Liz added.
The heartbroken mum said after the trial that the conviction at Dublin Central Criminal Court at least gave her peace of mind.
"There will always be a gap in our lives without Stephen, but at least now I know the man responsible is behind bars."