Rodney Clavell's grieving son in jail

The incarcerated son of fugitive Rodney Clavell, who shot himself during a siege, was having a hard time grieving as his father had been in the same jail, a judge has been told.

Richard James Clavell also now realised "the stark reality" of what will happen to him if he continues living a criminal lifestyle, his lawyer Peter Morrison told the SA District Court on Wednesday.

He asked that a merciful non-parole period be imposed on the 29-year-old, who was found guilty of drug trafficking and gun offences which occurred in Adelaide in September 2013.

Clavell's father, a 46-year-old former prison guard with a long criminal history, fatally shot himself after a 13-hour siege in an Adelaide brothel in June 2014.

His son was convicted after a loaded rifle fell from under his armpit as he attempted to flee police when they found methamphetamine in a bum bag around his waist.

Officers repeatedly used capsicum spray on Clavell, who had been smoking meth, but it had little effect on him and they called for backup.

On Wednesday, prosecutor Stephen Plummer described the offending as serious, saying he had a history of firearm offences and the latest were committed soon after he was released on parole.

But Mr Morrison said his client's life had forever changed because of his father's death.

"It is distressing for him, to say the least, made more so because he could not attend his funeral and could not say goodbye to him formally," he said.

"It is not a loss that is easily put to one side.

"His father's death was obviously high-profile and makes it more hard to get over."

His father was imprisoned in the same area of the jail where his son was housed and he once was offered the cell his father had occupied.

Clavell was constantly reminded of his father, which put him in a situation where his jail time was harder than usual.

His father's death had given him an insight into the fact that such a lifestyle could lead to more prison time or death, Mr Morrison said.

Clavell, whose father had been overbearing and aggressive, realised he had wasted his life and was now at the crossroads, he added.

He will be sentenced on March 16.

* Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14 or MensLine Australia on 1300 78 99 78.