Inferno: Katie Foreman's home on fire.

Inferno: Katie Foreman's home on fire. Photo: Supplied

A man at the centre of a manipulative love triangle, who convinced one of his lovers to murder the other by setting fire to her bedroom as she slept, has been sentenced to at least 27 years' jail.

The woman who helped start the fire has been sentenced to a minimum of 18 years' jail.

Solicitor Katie Foreman, 31, died as she tried to escape her home in the Wollongong suburb of Corrimal in the early hours of October 27, 2011.

Aftermath: The house after the fire.

Aftermath: The house after the fire. Photo: Kirk Gilmour

"The deceased was confined within an inferno that exploded in the quiet of the night in the home where she lived," Justice Ian Harrison said in handing down the sentence on Monday.

"It is difficult to contemplate ... a more excruciating or frightening way to die."

The fire was lit by Wendy Evans, 41, a former employee of the Department of Attorney-General and Justice, and another man who cannot be named.

Died in fire: Solicitor Katie Foreman.

Died in fire: Solicitor Katie Foreman. Photo: Supplied

They crept into Ms Foreman's home in the middle of the night, poured petrol on to her bed and then threw a bundle of lit firelighters into the doused room before fleeing the scene.

The court heard that the driving force behind the murder was Bradley Max Rawlinson, who was having intimate relationships with both Evans and Ms Foreman.

Rawlinson, 42, lied to Evans, telling her that Ms Foreman had threatened to kill a member of his family and to "end me".

He told Evans that the only way for them to be together was for the solicitor to be killed.

"Just keep thinking, one more week and we're away from her," Rawlinson told Evans in a text message before the murder.

At the same time he was sending Ms Foreman declarations of love, including one message in which he declared "hi beautiful, I can't wait to see you".

Believing Rawlinson's lies, Evans plotted the murder, bringing in Michelle Sharon Proud, who was also sentenced to 14 years' jail on Monday for her role in the murder.

"I'm satisfied that her participation came about, to a considerable degree, under the influence of Mr Rawlinson and the web of lies and deceit he had spun," Justice Harrison said.

"He manipulated her emotionally and psychologically, painting the deceased as an immovable object to them growing old together."

After the murder, Rawlinson turned on Evans, telling police that it was she who had been manipulating him, and had threatened to kill the member of his family.

These claims, Justice Harrison said were so unbelievable they "bordered on the bizarre".

Rawlinson was sentenced to a maximum of 36 years in jail with a non-parole period of 27 years. Evans was sentenced to 24 years' maximum with a minimum of 18.

Proud was sentenced to 20 years' jail, with a non-parole period of 14 years, for her role in the murder.

Proud, 29, arranged for a man to hurt Foreman in exchange for payment from Evans and Rawlinson. 

"She was a willing and enthusiastic contributor in the plan to cause very substantial harm to the deceased," Justice Harrison told the court. 

Justice Harrison said he accepted Proud had not known of any intention to kill Ms Foreman, referring to her "naïvety and ignorance". 

The judge also took into account Proud's special circumstances, including a major depressive illness and her precarious financial situation.

- with Patrick Begley