Boy, 13, Died in a Firebomb Attack During His First Sleepover — Now the Man Behind It Is Going to Prison By Gabrielle Rockson

A man has been jailed for starting a 1998 fire that killed a 13-year-old Australian boy during his first sleepover.

On Tuesday. Dec. 22,  at the NSW Supreme Court, Gregory John Walker was sentenced to a maximum of 10 years and nine months in prison in connection with the death of Arthur Haines, according to news.com.au, the Australian Broadcasting Corporation (ABC) and The Guardian.

While he was charged with Haines’s murder in 2022, Walker pleaded guilty to manslaughter before his Supreme Court trial earlier this year.

On April 9, 1998, Haines was sleeping at a friend’s home in Sydney when Walker threw a Molotov cocktail into the residence, according to news.com.au. Walker launched the attack because he believed a neighbor was responsible for paint-bombing his partner’s car, ABC reported.

Although Walker claimed he didn’t know anyone was inside, he drove to the back of the house and threw the device over the fence, intending for it to land on the back veranda, news.com.au reported. Instead, it landed in the kitchen.

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PEOPLE has contacted NSW Supreme Court for comment, while NSW Police Force declined PEOPLE’s request.

Haines, who had been sleeping upstairs,  jumped from the window, The Guardian reported.

Sustaining burns on up to 65% his body, the teen died in hospital 11 weeks later.

Speaking at Tuesday’s hearing, Justice Hament Dhanji told the court, “The results were catastrophic,” according to The Guardian.

Walker kept his eyes down during the sentencing.

He reportedly told a witness in 2014 that he “wouldn’t have gone through with it” if he knew children were inside the home.

In 2020, Walker was arrested after the NSW Police Force offered a $1 million reward over information about the 1998 incident.

The judge told the court that the former boxer had a long criminal history dating back to the 1980s, but had since turned his life around, setting up a not-for-profit boxing gym for young people.

“It appears he has steered a number of young people away from the path he went down,” Justice Dhanji said, per ABC. “While the ledger cannot be squared by the good of the offender in more recent times, that contribution must be taken into account and given weight.”

In a letter to the judge, Walker apologized to Haines’s family, saying he felt “shame and embarrassment” over the incident, ABC reported.

“There are no words I can say that can ever bring back Arthur and I have been living with guilt, shame and regret over what happened for decades now,” he wrote.

He added that it was never his intention “to actually hurt anyone that night, let alone take someone’s life.”

Walker is eligible to apply for parole in February 2029 due to being in custody since 2022.

Haines’s mother, Julie Szabo, says she replays the sequence of events in her mind.

“It was going to be the first night he had not slept under the same roof as me,” her statement read, per The Guardian. “I said ‘yes’ … I think about that decision a lot.”

She added, “I gave him the biggest hug, we both said we loved each other, I didn’t know at the time it would be one of our last hugs.”