No bitterness when she discusses a murder that shocked Tasmania for its single-minded brutality and callousness.

But what lingers, besides endless pain, is disbelief that such a crime could ever be committed.

And worry about what’s to come when the Launceston murderer is released into the community.

On February 19, 2005, Matthew Gouldthorpe was mowed down and killed in Launceston.

The hit-and-run was not an accident or recklessness but a ‘‘joke’’.

The 19-year-old had moved to Launceston to pursue a passion for aquaculture at the Australian Maritime College.

It was just day three in Tasmania when Matthew got lost on Dowling Street in the early hours of the morning and flagged down a passing car for directions.

The driver Shane Anthony Mayne, 27, and passenger Michael John Brown, 23, laughed in his face and drove off.

What happened next is chilling.

Brown turned to Mayne and suggested he run over the lost kid.

And so he did, crossing onto the wrong side of the road, mounting the footpath and clipping Matthew.

Not finished yet, Mayne did another U-turn and chased the helpless teenager down.

When he hit Matthew the second time the car was estimated to be doing up to 83km/h.

Matthew got caught under the vehicle and still Mayne did not brake. Instead he dragged the victim another 20 metres before coming to a stop and taking off.

He would later tell police ‘‘it seemed funny at the time’’.

Mayne pleaded guilty to murder and got 25 years – 14 non-parole.

Inconceivably for the Gouldthorpes, Brown was out on parole in under four years after being found guilty of manslaughter.

It’s now the potential release of Mayne in just four years that fills the Gouldthorpes with dread.

‘‘It’s like I’m preparing them for his release, every mother and their child,’’ Mrs Gouldthorpe said in Launceston this week.

‘‘Because I know and they know when he’s released, all the care they have to take when they come across him. 

‘‘It sounds bizarre but he’s going to be here.’’

Matthew’s father Howard is still haunted by the killers’ ‘‘lack of remorse or contrition’’.

‘‘If [Mayne] has no regret it makes you think – is he going to hit someone else or maybe it will be another ‘joke’,’’ he said.

‘‘Is the community safe?’’

A decade on and the couple tries to think about the life their son would have had if it wasn’t taken by Mayne and Brown.

‘‘I can’t help but think of that because his friends still come and see me and they’re all getting married, they’ve got good jobs and I often think where he’d be at,’’ Mrs Gouldthorpe said.

‘‘He would probably have stayed on in Launceston. This would have been more his lifestyle than the city of Melbourne.’’