A man who stabbed his parents to death and tried to kill a family friend because he was hearing voices had no contact with any mental health agencies before the incident.

Coroner Erin Woolley determined there was no need for an inquest into the deaths of Herman and Elizabeth Bangera in their Auckland home in March 2021 because there was no suggestion anything could have been done to prevent the offending.

The relevant matters had been resolved in the criminal court process and further coronial inquiries were not needed, she said.

On March 19 2021 the couple were at home with their son Sheal when he became agitated and started acting aggressively.

The couple attempted to talk to Sheal and Elizabeth Bangera contacted a close family friend, asking him to come and help them.

When the friend arrived Sheal was outside “pacing up and down” in a courtyard area at the back of the house.

Soon after Sheal went inside and obtained a large kitchen knife from the kitchen bench.

When his parents and their friend went to speak to him he lunged at them with the weapon.

Herman and Elizabeth Bangera suffered fatal injuries at their Epsom home. Photo / Supplied

He tried to stab the friend in the chest but his parents managed to pull him away.

The friend went inside to call 111 and Sheal turned on his parents.

He stabbed Elizabeth Bangera, 55, in the neck and back.

She staggered inside and collapsed from blood loss.

Herman Bangera continued to struggle with Sheal outside and was stabbed six times - twice in the front of his torso and four times to his back.

He also managed to get inside and collapsed near his wife.

The Bangera’s friend locked the door as Sheal started to stab himself in the abdomen and chest.

Emergency services arrived soon after and attempted to save Herman and Elizabeth Bangera but their injuries were too severe.

Sheal was rushed to the hospital and underwent surgery for his injuries.

He was later charged with the murders of both of his parents and the attempted murder of their friend.

He pleaded not guilty by reason of insanity.

In March last year, Sheal Bangera’s plea was accepted in the High Court at Auckland.

On March 22, 2021, police descended on an Epsom home where Herman and Elizabeth Bangera were fatally stabbed. Photo / George Heard

Justice Sally Fitzgerald said she was satisfied, on the basis of expert evidence, that Sheal was insane at the time of the offending.

She said the expert presented to the court outlined that he had been diagnosed with schizophrenia “following” the offending and that he was suffering from overwhelming psychotic symptoms at the time of the fatal stabbings.

In June Justice Neil Campbell made an order detaining Sheal Bangera in a forensic psychiatric facility as a special patient.

As per New Zealand law, the killer will now remain in the facility until the Minister of Health or the national director of Mental Health deems he is no longer a risk - a period that potentially could be longer than a prison sentence had he been found guilty.

In court, Justice Campbell explained that he was satisfied this order was necessary to achieve Sheal’s rehabilitation and reintegration into the community.

Further, he said there was a clear risk that he might experience a schizophrenic relapse, and there was a demonstrated nexus between his mental illness and his violent offending.

The court had earlier heard that at the time of the killings, Sheal was hearing “Satan’s voice” telling him that “love existed” but “God’s voice told him it did not.”

Herman Bangera (left), Sheal Bangera and Elizabeth Bangera (right) at Sheal Bangera's graduation in 2014. Photo / Supplied Photo/supplied

He believed the family friend was the “materialisation of Satan” and was controlling his parents.

“He said he felt compelled to kill himself to prove that love existed,” a psychologist reported.

“He expressed a belief that the events of that morning were being monitored or broadcast.”

Since the case was disposed of in court Coroner Woolley has been considering whether an inquest was needed.

Inquests are held so Coroners can assess whether any recommendations need to be made that could prevent the occurrence of similar deaths in the future.

Coroner Woolley said that give Sheal Bangera had not engaged with mental health services before the incident an inquest was not needed.

“Both of the expert reports provided to the High Court to assist with the issue of insanity and disposition outline that Sheal did not have any previous contact with mental health services prior to the offending, not had he committed any other criminal offending,” she said in a ruling provided to the Herald.

“I have had regard to police documentation, the decisions of Fitzgerald J and Campbell J and the expert reports provided to the High Court at Auckland about Sheal’s mental state.

“I am satisfied that the matters… have been adequately established in the course of the relevant criminal proceedings and investigation.

“I am satisfied that there are no other matters which require a coroner’s inquiry to be opened.”

Police at the scene of the double stabbing. Photo / Alex Burton

Police described the deaths of Elizabeth and Herman Bangera as “an absolute tragedy”.

Herman Bangera was said to be a “lovely man and wonderful dad”.

Elizabeth Bangera worked at the University of Auckland and a spokesperson described her as a “highly respected colleague and friend”.