A psychologist said the Auckland South Corrections Facility prisoner had "a very limited understanding of his high risks and how to deal with them".
And Rouvi's written safety plan also left Parole Board chairman Sir Ron Young with significant doubts.
"It did not have the ingredients of a safety plan and was difficult to read. It did not have any proper structure to it, and it was difficult to believe that that was the result of the work that had been done with the psychologist," he said.
Aranui had ended her relationship of five years with Rouvi after finding messages on his phone which suggested he had been unfaithful.
She went to their Bay View Rd home to tell the rest of the family she was moving out.
After an argument outside, Rouvi took two boning knives from his car and attacked the woman, inflicting 21 injuries.
Aranui's screams brought the killer's then 29-year-old son out of the house. He tried to distract his father so the victim and other family members could escape.
Rouvi briefly gave chase before giving up and stabbing himself five times in the chest.
The victim died in a carport about 70m away.
The Parole Board heard Rouvi was now a minimum-security prisoner and was housed in the facility's self-care units.
He had been on three guided releases to Hamilton without incident.
"With proper accommodation and a completed safety plan, Mr Rouvi may well be a reasonable candidate for release," Sir Ron said.
He will come before the board again in October.
