Justice Sean Cooper stopped addressing the jury on Tuesday and cautioned the gallery after a handful of people began arguing at the Brisbane Supreme Court trial.
"Hey, that's enough," he said.
Moments earlier words had been exchanged in the gallery at Joshua Lindsay Elkerton-Sandy's trial, prompting security to tell a man to be quiet or he would be removed.
Soon afterwards there was another exchange before the woman left crying, prompting the raised voices that earned Justice Cooper's warning.
The bailiff then approached the gallery and a woman said: "He's made my sister feel so uncomfortable she's walked out".
"If you are not quiet you will be asked to leave and you will not be allowed back in. Please be quiet," the bailiff replied.
Another member of the gallery began to protest before the bailiff said: "That's it - that's your last warning".
Elkerton-Sandy, 21, is on trial after 18-year-old Kane Alexanderson was fatally stabbed on Australia Day 2020 in a Brisbane CBD high-rise building.
A fight erupted after two groups having separate parties in different buildings became aware of each other.
"They could see each other on their respective balconies and words involving yelling and swearing were exchanged," crown prosecutor David Nardone said.
Mr Alexanderson and eight others left their gathering and "snatched" a security swipe card to gain access to the level 17 apartment party that Elkerton-Sandy was attending in the other building.
A fight erupted after they entered the apartment and three members of the group including Mr Alexanderson were stabbed, the court heard.
One was slashed in the face, another in the torso and arm while Mr Alexanderson was stabbed twice, Mr Nardone told the jury.
Mr Alexanderson suffered a 6cm deep wound that penetrated his heart.
He died six days later.
"There will be no ... contest that Joshua Elkerton-Sandy caused Kane Alexanderson's death," Mr Nardone said.
"The question becomes did Joshua Elkerton-Sandy lawfully act in self-defence."
Mr Alexanderson's group was "up to no good" when they headed toward the other party, Mr Nardone said.
"They seemed committed to confront and perhaps even assault the accused," he said.
Seven of the nine-strong group were able to enter Elkerton-Sandy's apartment, the court heard.
The fight lasted less than a minute before Mr Alexanderson's group fled when they became aware of a knife, the jury was told.
Members of his group helped Mr Alexanderson down to the ground floor, at one stage taking the fire exit stairs because the "lift didn't come fast enough", before calling an ambulance.
In a police interview Elkerton-Sandy claimed Mr Alexanderson was accidentally stabbed by a member of his own group who had an "army blade with serrated edges", Mr Nardone said.
In another he said his friend stabbed Mr Alexanderson and the others.
He also told an undercover officer in a watch-house cell that he knifed all three including Mr Alexanderson "twice in the guts", Mr Nardone said.
Elkerton-Sandy has pleaded not guilty to manslaughter.
The trial continues.
7°C