Jealous doctor is sentenced to life behind bars for stabbing his socialite lover Maureen Boyce to death inside her penthouse apartment after being found guilty of murder a SECOND time

 A retired US doctor who murdered his Brisbane lover, leaving a knife embedded in her abdomen, has been sentenced to life in prison for a second time.

Thomas Chris Lang, now 68, denied murdering socialite Maureen Boyce whose bloodied body was discovered in her Kangaroo Point penthouse on the morning of October 22, 2015.

But after three days of deliberation following a two-week retrial, a Brisbane Supreme Court jury on Monday delivered a guilty verdict.

When asked if he had anything to say after the verdict, Lang said: 'Yes, because I didn't do it.' 

Former model Maureen Boyce was stabbed five times while asleep in her bed. The attack was so savage that the kitchen knife went all the way through her abdomen and pierced the sheets

Thomas Chris Lang pictured in 2017. The former doctor has been sentenced to life in prison after being found guilty of Ms Boyce's murder for a second time

Maureen Boyce's family outside court in 2017. Pictured: husband Graham , son Zachary and and daughter Angelique Pennisi . Maureen never got to see her grandchildren

During the 1960s and 1970s Ms Boyce was one of Australia's 'top models', going by her maiden name, Maureen Madden

Lang's first conviction in 2017 over his lover's death was quashed on appeal last December when the Court of Appeal found there was a 'real possibility' that misleading and irrelevant evidence was used to convict Lang.

The former fashion model and mother of two was stabbed five times with a kitchen knife with such force that the blade pierced the blood-stained bedding beneath her three times.

'She was found with a kitchen knife embedded in her abdomen down to the hilt,' crown prosecutor Todd Fuller told the trial.

'The tip of which had penetrated through to her back, on the opposite side into the sheet on the bed below her.'

Lang was the only other person in the apartment on the night she died, and the jury rejected his claims that Ms Boyce committed suicide.

Instead, it found Lang stabbed Ms Boyce in a jealous rage after she threatened to 'hook up' with an ex-boyfriend.

Lang told police it was like a 'stab to the heart' to discover she was still in contact with her former lover. 

Crown prosecutor Todd Fuller told the court Lang had been 'driven to the edge' by Ms Boyce messaging another man.  

Maureen Boyce pictured with daughter Angelique pictured at the 2002 Melbourne Cup. The grieving family was cruelly robbed of their mother and wife by Thomas Chris Lang

'This man here ... was driven to the edge by her duplicity,' Mr Fuller said.

'When I say history repeating itself, he was being betrayed by her for the second time, not the first.'  

In sentencing, Justice Ann Lyons said Lang had lied about the critical events leading up to the 'vicious attack'.

'We don't know the full extent of the circumstances of that murder because you lied about those critical events,' Justice Lyons told Lang, as reported in the Courier Mail.

'You clearly then lied further when you rang triple-0, and when you met police in the unit that morning and in your formal records of interview when you gave elaborate and evolving explanations involving that she suicided.'

'We do know there were four or five thrusts with the knife which severed her liver… those thrusts were so deep they resulted in three exit wounds which pierced the sheet she was lying on.'   

Maureen Boyce's son Zachary and husband Graham pictured in 2017 outside court

Thomas Lang will be eligible for parole in 15 years having spent 5 years in jail already

Justice Lyons said the evidence showed the blade had been almost fully withdrawn after the first two thrusts before being rotated between 90 and 180 degrees and thrust into her chest cavity.

'Those wounds caused a haemorrhage and she bled profusely into her abdomen, she would have then gradually lost consciousness,' Justice Lyons said.

'Just reciting those facts indicates the viciousness of that attack.'

 'The jury were clearly satisfied unanimously that she had not committed suicide as you had alleged.'

Justice Lyons said Lang had killed a defenceless woman who was most likely fast asleep in her own bedroom.

Socialite Maureen Boyce was found in her Kangaroo Point home with a cooking knife so deeply embedded in her stomach she was impaled to the bed

Ms Boyce's husband Graham and her children told the court that the former model had been thrilled to learn she was about to become a grandmother.

They told of their heartbreak that she was killed before the arrival of her first grandchild.   

Justice Lyons sentenced Lang to a maximum life sentence, saying the circumstances of her death had caused great and continuing distress to her family. 

'Her family have been deprived of her vibrancy and her love. It is a cause of great sadness that she will never get to meet her grandchildren,' she said. 

'They clearly all miss her deeply, that was obvious in their evidence to the court. And it's the cause of great sadness that she did not get to meet her grandchildren.' 

Lang has already served five years in prison since Ms Boyce's 2015 murder and so will be eligible for parole in about 15 years, taking into account time served. 

Maureen Boyce with son Zachary Boyce . Zachary said her death caused great harm to the family, as his mother had two children and was soon to become a grandmother

Ms Boyce and Lang had known each other for more than 30 years and had indulged in an extramarital affair in the United States in the 1970s.

When Ms Boyce returned to Australia, she was pregnant with Lang's son who she raised with husband Graham.

Ms Boyce told Lang about his son in 2013, and the pair rekindled their relationship in the years leading up to her death.

Lang claimed the pair were engaged and intended to wed before Christmas.

He had repeatedly claimed Ms Boyce committed suicide after becoming upset that her multimillion-dollar Kangaroo Point penthouse had failed to sell to prospective buyers.  

Outside the court, family members embraced after the verdict that came more than five years after Ms Boyce's death - but not everyone was satisfied with the result.

A lifelong friend of both Lang and Ms Boyce broke down in tears and confronted detectives, saying they would 'rot in hell'.

'I am terribly, terribly disappointed. I met Dr Lang with Maureen ... he loved her to bits. He was the love of her life. He is a lovely man, he wouldn't kill a fly,' Jocelyn Banks told AAP outside court.

'They were madly, madly in love. To think that anyone could believe he had done this is beyond comprehension.

'She was the one who tracked him down - it's a tragic second-time-around love story.'