A Mongols bikie who opened fire in a busy Gold Coast shopping centre has had his sentencing adjourned after revealing he is bipolar.

A gunman who shot an innocent bystander while trying to murder a rival bikie in a busy Gold Coast shopping centre has had his sentencing adjourned after it was revealed he is bipolar.

Mongols bikie Mark James Graham, 28, opened fire on then-Bandidos gang member Jacques Teamo at the busy Robina Town Centre shopping precinct in April 2012.

One of Graham’s two shots also hit bystander Kathy Devitt in the buttock.

A Supreme Court jury in Brisbane on Tuesday found Graham guilty of Teamo’s attempted murder and unlawfully wounding Ms Devitt while intending to maim Teamo.

Justice Alan Wilson was due to sentence Graham on Wednesday, but defence barrister David Edwardson told the court his client only told him that morning he had been diagnosed with bipolar disorder.

Mr Edwardson said Graham was on anti-psychotic medication Seroquel.

He said the diagnosis would affect sentencing and he wanted an adjournment to obtain a psychiatric report.

“I need to explore this condition that I wasn’t aware of until today,” Mr Edwardson said.

Justice Wilson agreed to adjourn the sentencing until November 3.

Graham pleaded not guilty to the attempted murder and unlawful wounding charges, but guilty to possessing a weapon.

During the trial, Mr Edwardson claimed Graham acted in self-defence after Teamo, who could be seen on CCTV footage waving his arms aggressively, pulled a knife on him.

But crown prosecutor Michael Byrne QC argued Graham’s actions went further than self-defence, particularly given Teamo quickly retreated after Graham pulled out his gun.

The incident was one of the key reasons for the Queensland government’s crackdown on controversial outlaw motorcycle gangs.