Man found not guilty of murdering father, now detained in psychiatric care

Police outside the property in Glendene where the 63-year-old man was fatally stabbed by his son. Photo / NZME

A man who was found not guilty by reasons of insanity after killing his father has been detained as a special patient at the Mason Clinic.

Authorities were called to a disturbance in Glendene, West Auckland in 2020, where Derek Lance McFarland was found seriously injured. He died at the scene.

A boarder who was living at the house with the victim and his son at the time of the attack described the events as an argument that escalated quickly over the son not taking his medication.

"I feared for my own safety so I locked myself in my bedroom and escaped out the window," a summary of facts provided to Open Justice said.

Dion McFarland, 39, was charged with murder. His father had been fatally stabbed in the neck, head and leg several times.

McFarland was arrested the next day and told police he didn't know why he did it.

In June, Justice Sally Fitzgerald ruled McFarland was not guilty for reasons of insanity after receiving two psychiatric reports prior to the hearing.

"They're very consistent and clear in their views, so I make a finding of not guilty by reason of insanity," she said.

In a recently released judgment, Justice Paul Davison made an order under the Mentally Impaired Persons Act, directing McFarland to be detained as a special patient at the Mason Clinic, a secure psychiatric facility.

In 2020, Dion McFarland was arrested and charged with murder after he fatally stabbed his father in the head, neck and leg. Photo / NZME

In last week's hearing, held at the High Court in Auckland, Justice Davison spoke about the man's mental health issues.

"The position is sadly but obviously very clear that he is suffering from mental disabilities, he needs to be supervised, it's in his best interest and the interest of the community."

Both the Crown and McFarland's lawyer agreed it was in the interests of protecting the public and also to ensure McFarland was treated correctly.

McFarland, who appeared via video link, had his lawyer tell the court he understood the decision and acknowledged the family members and others who have been in court since 2020.

One family member present in court shook her head in disbelief.

In a decision released to Open Justice after last week's hearing, forensic psychiatrist Dr Wee Lee Chua said the defendant would benefit from the most intensive and focused rehabilitation.

Chua said McFarland's risk was mitigated by being in a medium secure rehabilitation unit and he would benefit from attending a violence reduction, alcohol and drug programme among other rehabilitation groups at the Mason Clinic, to improve his understanding of the offence and the risk of violence.

"Having considered the contents of Dr Chua's report, I am well satisfied that it is appropriate for the defendant to be detained in a hospital as a special patient under the Mental Health (Compulsory Assessment and Treatment) Act 1992," Justice Davison said.

"[McFarland] is to be detained at the Mason Clinic where he can receive ongoing rehabilitation and external supervision."