Shane Anthony Mayne was jailed for 25 years in 2005 with a non-parole period of 14 years after pleading guilty to murder.

Mr Gouldthorpe had only been in Launceston three days when he was mowed down by the then 27-year-old Mayne on a footpath in Dowling Street after asking for directions.

Passenger Michael John Brown suggested Mayne should hit Mr Gouldthorpe, so the killer did a u-turn, crossed onto the wrong side of the road, mounted the footpath and sideswiped the man.

Mr Gouldthorpe fled on foot, but Mayne pursued him, hitting him again but this time at somewhere between 71 and 83km/h.

The killer stopped briefly to look at the body on the road and fled the scene. He was caught by police shortly after.

Mayne initially told police Brown was driving, but later made full admissions.

The killer was eligible for parole on February 18, with his initial application on February 8 refused by the parole board.

It was recommended Mayne complete a program at the Apsley Drug Treatment Unit and concentrate on his internal behaviour before re-applying.

Mayne followed through on both suggestions, with the parole board saying he stopped engaging in internal offending after the February decision.

"The exit report from the Apsley Drug Treatment Unit identified that there has been a growth in the applicant's confidence whilst undertaking the program and the applicant meaningfully engaged in the course work," the board said.

He appeared again before the board on May 10 but proceedings were adjourned until July 12 while a psychological assessment and report could be completed.

The assessment identified some risk of institutionalisation of Mayne, with his family also considered a risk due to potential exposure to destabilising factors and substance abuse.

Strong supervision of Mayne was required, the report said.

"There are, however, positive plans identified including engagement by the applicant with church based support and counselling," the board said.

Mayne told the board he reflected remorsefully on his actions every day.

During sentencing, Justice Ewan Crawford said Mayne's violence and contempt for another human being could only be regarded with horror and utter disgust.

"It was random violence, one of the worst examples with which I have had to deal," he said.

"Apart from his eventual confession and expression of regret, along with his plea of guilty, little could be said for him by way of mitigation.

"He is mildly intellectually disabled with a tendency to act impetuously and to be easily led, but those factors provide no real excuse."

The parole board noted Mayne had been polite and compliant during his time in prison, holding the position of wardsman and discharging that work to a high standard.

He also engaged in a number of therapeutic and vocational courses and was given approved leave to work as a volunteer at the RSPCA in 2017.

But that leave was revoked after the killer admitted to trafficking tobacco into the prison for personal use.

Similar behaviour occurred in 2018 when he was given leave to volunteer at the Tasmanian Dogs Home, with Mayne bringing unauthorised items into the prison because he was "under pressure" by other inmates.

Mayne's lengthy criminal history includes a number of prison sentences and charges for assault and aggravated robbery.

"Factors that have been found contributory to the offending behaviour includes the use of illicit drugs and the fact that he is easily influenced," the board said.

Mayne was released on July 23, with a parole period active until February 2030.