Karen Ristevski's friends enraged by Sarah's continuing defence of killer father

A childhood friend of slain Melbourne mother Karen Ristevski has spoken of her disappointment, after Karen's daughter used a tell-all interview with 60 Minutes to defend her killer father.

"It makes me very angry but also very, very sad," the friend, who only wanted to be known as Sam, told A Current Affair.

Choking back tears, Sam said the interview with Sarah Ristevski left her with more questions than answers.

"I had hoped to get closure last night," she said.

"I feel for Stephen, Karen's brother, and the rest of her family."

Another close friend, Sharryn, said Karen's only daughter Sarah "was her life".

"From what Karen used to say, they spoke on the phone at least six to eight times a day.

"They were very, very close, so it very much surprised me it was one-sided."

Criminal psychologist Tim Watson-Munro said while Sarah's unwavering support for her killer father was unusual, it wasn't unheard of, especially in cases involving family violence.

"There was nothing that I detected that would suggest she's brainwashed," he told A Current Affair.

"We don't know the bond that went on in that family but clearly it was a strong bond.

"There may be a degree of denial as a defence mechanism, but it's clear she wants to maintain the relationship with her father – she may believe him, who knows."