The getaway driver for the Panmure RSA killings is to be freed from prison on Monday.
In 2001, Darnell Tupe lay in wait while William Bell killed three people and left a fourth person for dead.
Tupe's 12-year sentence for manslaughter and aggravated robbery was due to end in December next year.
The Parole Board says he expresses profound remorse for his actions.
It says the 33-year-old can't be offered any further treatment in prison, after undergoing two rehabilitation programmes and a drug and alcohol course.
Although psychologists believe he still poses a moderate risk of violent reoffending, the board has decided he can leave prison to live with his father under an overnight curfew.
The sole survivor of the attack, Susan Couch, says Tupe's release is a shock, even though she knew it would happen sooner or later.
