Megan Somerville found not guilty of stabbing children by way of mental incompetence

In a frenzied attack she said was fuelled by fear predators were going to kill her and her children, a mum pulled over on a major highway and stabbed her children. Now, she won’t face a trial.

A Supreme Court Justice has found that a mother who pulled over on one of Adelaide’s biggest highways in the middle of the night and stabbed her two children was in a state of self induced intoxication – but she won’t ever face a criminal trial for the actions.

On Thursday afternoon, Justice Sandi McDonald found Megan Jayne Somerville, 37, not guilty of attempting to murder her two sons in 2022 by way of mental incompetence.

Justice McDonald found, beyond a reasonable doubt, the mother had stabbed her two children on the side of the North South Motorway but did not know her actions were wrong.

“The objective elements of the offences are established beyond reasonable doubt,” she said.

“Ms Somerville was mentally incompetent to commit the two offences of attempted murder and at the time of the incident, she was suffering from mental impairment and as a consequence did not know that the conduct was wrong.”

Megan Jayne Somerville, 37, of Modbury Heights, accused of stabbing her two sons in the middle of traffic on the North-South Motorway on Monday night. Picture Facebook

However, Justice McDonald found that her mental state at the time of the incident was self induced.

“Her mental impairment was substantially caused by self induced intoxication,” she said.

“Ms Somerville is not guilty of the offences of attempted murder by way of mental incompetence.”

On August 15, 2022, police were called to the North-South Motorway just before 11:30pm following reports a woman had been detained by a member of the public.

Megan Jayne Somerville has been found not guilty by way of mental incompetence. Picture Facebook

The court previously heard Ms Somerville, of Modbury Heights, stopped her silver Honda sedan and removed her two sons, aged 3 and 8 at the time, before stabbing them “a number of times” with a knife.

The court also heard that she was under the effects of meth, cannabis and prescription medication that night.

A forensic psychiatrist who assessed her also told the court Somerville’s recount of the incident included her fear that she and her children were “facing a fate worse than death”.

“She had such severe delusions that were of a certain nature that meant she thought her children were in danger of a fate worse than death, that they were being groomed to kill her, and when that was done, they would be abducted, tortured and killed,” he said.

“In harming the children, she thought she was doing the right thing in the circumstances.”

On Thursday, prosecutor Lucy Boord SC told the court there would likely be a victim impact statement at the next hearing.

Somerville will return to court in June.

Originally published as Megan Somerville found not guilty of stabbing children by way of mental incompetence