Phillip John Smith, 39, was earlier this month declined an early release.
The Parole Board on Wednesday released its reasons for declining parole for the second time.
Smith was jailed for at least 13 years in 1996 for murdering the boy’s father in his Johnsonville home.
In 1995, despite the family being relocated, Smith, who was on bail on charges of molesting the 12-year-old boy, found them and broke into their house where he stabbed the boy and then the father fatally.
This year, a psychologist assessed his risk of general reoffending as high, but said it was most likely to take the form of fraudulent offending.
The psychologist said the murder occurred in a situation when Smith “felt trapped and extremely vulnerable”.
But Justice Warwick Gendall said the board did not accept the claim that Smith murdered the father in a spur-of-the-moment panic.
It would be premature to grant parole on the basis he has had several temporary releases and a strong support group, Justice Gendall said.
“His risk is, and has been, such that he needs to prove himself in wider range of situations, and over time, in the community.”
After being jailed, in 2011 it was revealed Smith had been able to stalk the victim’s family, sending an associate to their house with the message “Smith says hello”.
From behind bars, Smith was also able, through a company he had set up, to sell Chinese electronics.
Smith was declined parole last year, with Justice Gendall saying the board believed he was still a serious danger to the community.