THE troubled, gun-wielding son of wanted fugitive Stuart Pearce can no longer be shown any mercy by the courts, a judge says.

District Court Judge Paul Slattery today jailed Matthew Pearce for 18 months over firearms offences, saying he had run out of chances.

Pearce was orphaned when his mother and siblings were murdered, and his father disappeared, in 1991.

Today, Judge Slattery said that tragedy had forged Pearce - but it could no longer excuse his conduct.

"There is little doubt that the heartbreaking events of your childhood have led to your life of criminality," he said.

"You have been in contact with the criminal justice system every year since 2001.

"This court cannot continue to show the mercy it has in the past."

Pearce, 30, pleaded guilty to multiple firearms offences relating to an incident in September last year.

Police searching for Pearce found him hiding in the roof of a house - while armed with a loaded gun.

They also found a backpack full of ammunition and a taser elsewhere in the house.

Psychological evidence tendered in court said Pearce was suffering from paranoid thinking, likely worsened by methylamphetamine use.

In sentencing today, Judge Slattery said penalising Pearce was difficult, as he had no fear of jail.

He said Pearce preferred imprisonment to liberty and "felt safer" while behind bars.

He urged Pearce to turn his life around for the sake of his son, now four.

"Each year you spend in prison is a year you do not get to play a hand in your son's upbringing," he said.

"You will be no sort of role model for him if you continue on this path.

"You know what it's like to grow up without a stable father figure ... I'm sure you do not want the same to happen to your son."

Judge Slattery imposed a nine-month non-parole period.

Originally published as Fugitive's son sentenced to jail