Mr Hayes, who had been shot in the arms, was also shot in the buttocks by Busch, then 32, as he escaped through a bedroom window.
At the time there had been allegations of a sexual relationship between Busch and the teenager. It is widely believed tensions were high between the three and that cannabis had played a part in the tragic event.
Police undertook the biggest manhunt of the time, looking for the murderer after he left the scene on his motorbike.
Two days later Busch handed himself in.
There was no trial as he admitted the charges and was sentenced to life imprisonment for murder and 10 years for attempted murder, to be served concurrently.
Busch was paroled in July 2002 but recalled within four months because of concerns over unsupervised conduct with children with suggestions of sexual grooming arising out of sexual tendencies identified since his arrest.
He went before the Parole Board last year when the board heard he had completed a prison sexual offender programme, was doing well on work-release and was attending church services with a supporter. The board refused to grant him parole then, with the head of the board Justice Warwick Gendall stating Busch had not done enough to "adequately address what appears to be a major risk factor, a component in the original offending, that being his understanding of his sexuality".
However, this time the board, headed by Judge David Holderness, heard Busch had a minimum security rating at the prison and was living in a Self Care Unit outside the prison.
It heard he has had a number of temporary releases to his sponsor's address without incident and his personal care officer spoke positively of Busch's increased maturity since being recalled.
The board's decision states Busch has had treatment with a psychologist and was considered at low risk of reoffending.
Discussing at length the ongoing effects of his offending, Busch told the board he had reflected constantly about this since his recall, the decision states.
He proposed to live in a caravan about 80 metres from his sponsor's home, on the same property.
The board reached the view, "Busch has a sound and robust release plan" involving employment and support and that with appropriate release conditions he now no longer posed a risk in the community and would be released with six conditions.
Busch is required to take part in a compliance hearing before the Parole Board in May 2014 to monitor his progress.