Shannon Brett Morrison not guilty of Sydney park stabbing attack

A jury has ruled a university cancer researcher was mentally ill when he attacked a group of teenagers with a knife in a Sydney park last year.

Shannon Brett Morrison. Picture: NCA NewsWire/Dylan Coker

A university academic has been found not guilty of stabbing a group of teenagers in a Sydney park after a jury found he was suffering from severe mental illness at the time.

Shannon Brett Morrison went on trial in the District Court for the attack just before midnight in Cameron Park, Turramurra on January 12 last year, which wounded several teenage girls and boys, aged 15 to 19.

Mr Morrison, 35, had pleaded not guilty to six counts of wounding with intent to cause grievous bodily harm, one of assault occasioning actual bodily harm and one charge of possessing a knife.

He was found not guilty on the grounds of mental illness for all counts.

Shannon Brett Morrison, left with mask, has been acquitted at trial. Picture: NCA NewsWire/ Dylan Coker

During the trial, the court heard the former University of NSW cancer researcher was extremely paranoid, installing security cameras at his home and “sleeping with a knife beside his bed” in the days before he went on a stabbing rampage.

It was argued the man from Sydney’s north shore was suffering from psychotic mental illness at the time of the incident, which may have been triggered by something in the park.

“He lashed out because he thought he needed to do what he was doing,” his barrister Phillip Boulten told the court.

He spent six months in custody after the stabbing in a park in Turramurra on January 12, 2019.

Mr Morrison had spent hours drinking with a date at Kiplings Garage Bar, located across the street from Cameron Park, before leaving around 11.30pm.

He ventured into the park after telling his date he needed to use the bathroom, before producing a flick knife when confronted with a group of teenagers.

Footage of police interviews in the aftermath of the incident showed one teen say Mr Morrison was “drunk off his head, telling us to go away” before he got out the knife and “started swinging”.

The jury heard six teens were stabbed, while another girl received a knick to her arm.

A teenage boy was slashed in the neck during the melee.

Mr Morrison’s bail will continue before he faces a hearing at Parramatta District Court on November 6.