Lawyers for Caroline Dela Rose Nilsson, charged with murder of her mother-in-law, say she had no motive

A woman accused of murdering her mother-in-law was a “nice, young girl” who was “so inherently unlikely ... to turn into some sort of psychopath”, her lawyer told a jury.

An Adelaide woman accused of murdering her mother-in-law was a “nice, young girl” who was inherently unlikely “to turn into some sort of psychopath”, a court has heard.

Closing their case before a Supreme Court jury on Friday, defence lawyers for Caroline Dela Rose Nilsson argued there was no evidence she had any motive to kill the older woman.

Nilsson, 29, has pleaded not guilty to the murder of Myrna Nilsson at the home they shared on Bunbury Terrace at Valley View, in Adelaide’s north, on September 30, 2016.

Police discovered the body of Myrna Nilsson on the laundry room floor and declared her dead at the scene, while the three young children of Caroline and her husband, Myrna’s son Mark, were also in the home.

The court has heard Caroline Nilsson told police that two or three men with “loud and angry voices” assaulted her, tied her up with speaker wire and tape, and ransacked the house.

Prosecutors argued her version of events didn’t make sense and alleged she staged the timeline and crime scene, but Heath Barklay QC, for Nilsson, said that idea was at odds with evidence before the court.

“It just seems ... so inherently unlikely that this nice, young girl, loving mother, (with a) good relationship with Myrna, is just going to turn into some sort of psychopath,” he told jurors.

“Kills her mother the minute she gets home ... searches the internet for a while, disposes of the bloody clothes and then presents as a victim.

“It just doesn’t fit with the picture that you’ve got of this woman.”

Mr Barklay said Nilsson was happy, “in love with her husband” and texting him nice messages in the lead-up to her mother-in-law’s death

“These are in the half an hour and up to the minutes before she’s then meant to turn into this cold-blooded killer,” he said.

A Supreme Court jury has heard Caroline Nilsson had no motive to murder her mother-in-law, Myrna Nilsson (pictured). Picture: Supplied

Earlier, prosecutor Emily Telfer SC said Caroline and Mark Nilsson paid Myrna $1000 a fortnight to stay at her house, Caroline had a $4000 debt, and the couple spoke of asking Myrna to loan them money.

The court also heard Myrna had bought their son, who was aged five at the time, a BMW and a condo in the Philippines.

“There is absolutely never a good reason to kill another person, much less a loved and valued family member,” Ms Telfer said.

“But you might think that the accused’s financial and social position would improve if her mother-in-law was out of the picture.”

She said relatives and friends, and even Myrna Nilsson, could have believed the relationship between the pair was respectful, but some challenges would have been alleviated if the family was “free of their mother-in-law”.

Disputing that notion, Mr Barklay said there was no evidence of a motive in the case, and jurors should avoid speculation.

He said Myrna Nilsson was a support to her daughter-in-law, and the court had not heard of any animosity between the pair.

“Everyone that knew them … thought that the two of them got along well,” he said.

The trial continues before Justice Chris Bleby and a jury.