A Dunedin teacher who stabbed her partner to death in the bath has been jailed for at least eleven years.

Carole Coade, 62, pleaded guilty to the murder of 58-year-old film-maker Mark Henry Willis in August and today, before the High Court at Dunedin, Justice Lisa Preston jailed her for life.

The victim’s family called the murder premeditated, a notion that was supported by Crown prosecutor Richard Smith who said the homicide exhibited a “high level of brutality, cruelty and callousness”.

Smith said the woman made at least three prior approaches or attempts to plan the killing of her partner, “out of fear of becoming destitute.

“She first tried to drug Willis with the intention that he would drown in the bath, the bath she encouraged him to have,” Smith said

The court heard Coade made her partner a coffee and laced it with her own crushed-up medication.

Willis had “tasted something was off” and immediately discarded it.

In the few days leading up to the stabbing, Coade said she felt increasingly disconnected with Willis and was succumbing to severely deteriorating mental health.

In early May when she saw her partner on all fours, cleaning the carpet, she approached him with a knife tucked into her trousers.

Carole Coade and Mark Willis.

A few days later she stood behind him with a knife as he sat at the computer.

Acknowledging her actions were “crazy” and out of fear of being overpowered, Coade withdrew from the attacks.

Smith said due to the looming pressure of a meeting with her employer, Coade felt it “had to be that day”.

Coade disclosed to a report writer that her attack continued until her partner went under the water.

Justice Preston addressed Coade in court.

“Yours was not a florid descent into an uncontrollable psychosis. You challenged your thoughts as crazy. You withdrew from medical support. . . . You didn’t feel like you loved him any more.

“In my view this was a brutal frenzied attack . . . ignoring his pleas: ‘No, Carole. I love you.”

Counsel Sarah Saunderson Warner said the crime occurred as her client was in a severe state of depression in which she suffered from “intrusive and ruminating thoughts . . . killing Willis was the only viable option”.

At 4.33pm on May 18 last year, Willis returned to his Tainui home and ran a bath.

Coade – who can finally be named after a suppression order lapsed today - armed herself with a 10cm long kitchen knife and entered the bathroom where she stabbed him 22 times.

Willis’ siblings said the killing of their caring, compassionate brother was inhumane and premeditated.

“I can’t imagine what Mark went through, I wonder what his last thoughts were . . . my baby brother.

“I still feel as numb as the day I was told.”

Eion Willis said his brother mistakenly put his trust in Coade and his death was “senseless.

“We were finally mates in our adult lives, something I yearned for . . . those hopes and dreams came crashing down with his passing.”

An autopsy revealed the depth of the stab wounds ranged from 11mm to 110mm.

One of them severed the left subclavian artery in the victim’s upper torso and a further four were inflicted to his lungs and liver.

At 5.15pm Coade sent a Facebook message to one of her children, stating: “I love you, I’m sorry for what I have done.”

Two minutes later she transferred $45,000 into their bank account.

She then called police, informing them of the bloody crime.

Officers found the man’s lifeless body in the bath.

Coade greeted police at the door, wearing blood-stained clothes - with superficial cuts to her hands.

Justice Preston acknowledged the crime was premeditated “through the lens” of Coade’s severe mental health issues but called it a tragedy, nonetheless.

“There is no doubt of the emotional devastation reaped on Mr Willis’ family and friends, they carry with them the pain and anguish of his loss.”