A Tasmanian woman and her "secret lover" have been found guilty of a "cold, calculated execution" that involved "a chilling betrayal of a friend and a husband".

It took a Supreme Court jury about five hours to find Margaret Anne Otto, 47, and Bradley Scott Purkiss, 43, guilty of murdering Tasmanian tattoo artist Dwayne "Doc" Davies.

In an emotionally charged hearing, Purkiss shook his head in the dock and Otto broke down in tears after both verdicts were read, while family members wept and hugged.

The body of tattoo artist Dwayne Robert 'Doc' Davies was found two years ago. ( Facebook: Ink Addiction )

While Otto was not present during her husband's killing, the court had heard she and Purkiss hatched a plan to murder Mr Davies to put an end to years of emotional abuse.

Purkiss lured Mr Davies to a property at Elderslie where he shot him at close range in the head in May 2017.

The court heard Purkiss then wrapped the body and buried his "best mate" in a shallow bush grave on a remote property at Levendale.

Crown Prosecutor Madeleine Wilson described the killing as "a crystallisation of a plan to kill Mr Davies that involved a chilling betrayal of a friend and a husband".

"There was deliberate and considered planning that led to an intentional killing," she said.

She said the plan had been in response to long-standing grievances.

Ms Wilson said both parties were motivated by a level of self-interest, whether that was to escape an unhappy marriage, financial issues, or a feeling of being used.

Purkiss interrupted Ms Wilson's final submissions.

"What a load of shit, you've got it all wrong," Purkiss said.

Chief Justice Alan Blow told him: "If you're not quiet, you'll be taken away."

The family and supporters of Dwayne "Doc" Davies outside court. ( ABC News: Phoebe Hosier )

Court hears of 'poisonous hatred'

Victim impact statements read to the court told of the destructive impact Mr Davies's death has had on his family.

Mr Davies's father, Glen Davies — who has buried two of his sons in the past six months — said he could not fathom how the wife his son adored, and her secret lover, had carried out such a "sickening act".

"I thought she hurt with us, was one of us — I considered her my daughter," he said.

Dwayne 'Doc' Davies' body was found in a shallow bush grave at Levendale in 2017. ( Supplied )

"I experience a surging, poisonous hatred for Ms Otto. It's inconceivable to think she had that evil in her … it's unfathomable."

He said photos of his late son Corey and murdered son Dwayne meant their family home "more resembles a death house than the happy home it once was".

The court heard Mr Davies's son was too disturbed by the "enormous impact" of his father's death to prepare a victim impact statement.

Purkiss 'the 'face of evil'

Mr Davies's sister, Kelly Goss said she did not know the friend she had known for 30 years had a "treacherous black heart" and was capable of such "depraved, sick behaviour".

She said Otto's ability to plan to murder her husband on her grandchild's first birthday sickened her, and that Purkiss's dark eyes and long stares were the "face of evil".

Speaking outside court, Mr Davies's father said he and his family were not surprised by the verdict.

"We're so pleased it's all over and we've got the verdict we were after," Mr Davies said.

"What they said about him in the courtroom was all lies; he wasn't like they portrayed him to be."

The court heard Mr Davies's drug habit had sent the family bankrupt and that Otto was a "model prisoner" who had shown extreme remorse.

"This is a rare occasion where there should be a substantial difference in sentences," Otto's defence barrister Greg Melick SC told the court.

The pair will be sentenced by Chief Justice Alan Blow on Wednesday.