RECORDED phone calls are expected to paint a true picture of how angry Rachel Narelle Smith was with her flatmate Amanda Quirk before her murder.
Smith, 41, is accused of being involved in beating and torturing the 32-year-old to death at their Booval home at Ipswich on the eve of Easter, 2010.
She is facing a trial in Brisbane Supreme Court after pleading not guilty to having a role in the murder.
Crown prosecutor Ben Power told the jury how Ms Quirk was bound with duct tape and gagged before she was "brutally tortured and beaten to death".
He said Christopher James Swan, 39, had already been jailed for life over the murder and for dumping Ms Quirk's body in forest in northern NSW.
Mr Power said to understand why it happened, the jury needed to "understand the household Amanda Quirk was living in at that time".
He said Smith "developed a strong dislike for Amanda" which was revealed through recorded conversations to Smith's partner in jail.
"She was angered by her belief that Amanda was 'bitching behind our back again and saying shit and dogging me out'," he said.
"This caused her to become extremely angry with Amanda, in (Smith's) own words to 'lose it'.
"On one occasion she said she had punched her full in the face and kept going and going because everything was building up inside her.
"So you can understand what the inflammatory effect of being told that Amanda had been speaking behind her back would have had on (Smith) on the day of the killing."
Mr Power said the violence in March, 2010, occurred after Ms Quirk's friend revealed she had told people there were drugs and guns in the house to get them "knocked".
He said she was beaten in bushland near Brisbane and then killed in the Dudleigh St house she shared with Swan and Smith.
"The reason is anger and revenge because a person said Amanda had told other people there were drugs and guns at the house," he said.
"The motive is a mixture of anger and revenge because Amanda Quirk was speaking behind people's backs".
The trial continues.
EARLIER: IT was while cleaning up the blood of her "best friend" that Michelle Anne Mondientz formed a new friendship bond.
"Friends forever," she said to Rachel Narelle Smith as their gloved hands used sponges to mop up evidence of a murder at a Booval home.
The blood belonged to Amanda Quirk, 32, who had just been "brutally tortured and beaten to death".
Mondientz, 35, says she was best friends with Ms Quirk since grade two.
Smith, 41, is facing a trial in Brisbane Supreme Court after pleading not guilty to Ms Quirk's murder.
The court heard on Thursday how Christopher James Swan, 39, had already been jailed for life over the murder and for dumping Ms Quirk's body in forest in northern NSW.
Ms Quirk had lived at 21 Dudleigh St for 10 to 15 years. Smith and Swan were new flatmates.
Crown prosecutor Ben Power told the jury they would hear evidence about how angry Smith was with Ms Quirk for speaking behind her back.
He said the Crown intended to prove Smith was directly involved in Ms Quirk's death or had aided and encouraged Swan.
But he told the jury they could also find Smith guilty on the lesser charges of manslaughter or accessory after the murder if they were not satisfied of the elements that went towards murder.
Mondientz was with the three flatmates on a return trip from Brisbane to get drugs when she revealed Ms Quirk had tried to get Swan and Smith "knocked".
She said she was also angry Ms Quirk had told people about her return to prostitution and began laying into her.
Mondientz said they stopped on a roadside near bushland where all three of them laid into Ms Quirk before Swan dragged her with rope into bushland and beat her badly.
She said she was dropped off when they returned to Ipswich but Swan called her later to help dispose of the body and clean up the blood.
The trial continues.