The son of former Adelaide Crows coach Phil Walsh has been found not guilty of murder by reason of mental incompetence in relation to his father's death by the South Australian Supreme Court.

Cy Walsh, 27, was detained in a secure psychiatric facility after he was arrested and charged with murdering his father in July last year.

Phil Walsh was repeatedly stabbed in his Somerton Park home in Adelaide's beachside suburbs in the early hours of July 3, 2015.

Cy Walsh (left) was left shattered by the death of his father Phil Walsh (right). ( Couchsurfing.com/Getty Images )

The 55-year-old was the head coach of the Adelaide Football Club at the time.

Cy Walsh pleaded not guilty to murder by reason of mental incompetence and at the last hearing the prosecution indicated it would accept that plea.

Justice Ann Bampton formally made a ruling that Cy Walsh was not guilty of murder by reason of mental incompetence.

She found the objective elements, or facts of the offending, proved.

That meant the court was satisfied Cy Walsh killed his father, but that he was not criminally responsible for his crime because of his mental state.

'My heart remains broken'

A victim impact statement was read to the court on behalf of Phil Walsh's wife, Meredith Walsh.

"My heart remains broken," she said.

"Our daughter is devastated by the loss of her father.

"Our son Cy is also shattered by what has happened, and has to live with the consequences of his illness, an illness that has destroyed our loving family."

Mrs Walsh also said privacy rules in relation to patients that have mental illnesses need to be readdressed.

She said there were two occasions when doctors told her son to continue to take his medications, but had not alerted the family of his need to do so.

"Because he was an adult the medical profession, as the law allows, didn't involve any other person with his health care," she said.

"This is where privacy issues need to be reviewed in these types of cases where someone's mental state is gradually escalating and putting themselves at risk."

She said family members of people suffering from mental illness needed to be told what was required in the way of medication, and the importance of being compliant with treatment.

"I know of others who have a family member with a mental illness who have also struggled to be part of the treatment and recovery process because they are excluded by privacy and confidentiality issues," Mrs Walsh said.

"There are other families just like ours whose lack of relevant information has devastating consequences.

"I will continue to love and support our son as his father and I have always done."

Cy Walsh suffered 'psychotic episode' the night of father's death

In her findings, Justice Bampton said she accepted the opinions of forensic psychologists that Cy Walsh suffered from undiagnosed and untreated schizophrenia.

"I find that Mr Walsh was not labouring under a drug-induced psychosis at the time of the conduct," she said.

"I find he was suffering a psychotic episode as a result of schizophrenia which at the time of the conduct was undiagnosed and untreated."

In her findings, Justice Bampton said toxicology evidence showed Cy Walsh was not intoxicated by any substance on the night of his father's death.

Extensive suppression orders on the evidence were reviewed on Wednesday afternoon.

Under South Australian law Cy Walsh will be subjected to a lifetime psychiatric supervision order, the terms of which will be determined by the court.

The case returns to court in December when the court will consider further reports on Cy Walsh's diagnosis, prognosis and a suggested treatment plan.