Teenage girl on trial for murder allegedly yelled ‘I told you I was crazy’ after alleged stabbing

A teenage girl who is on trial for murder allegedly yelled “I told you I was crazy” moments after she stabbed her boyfriend’s mate.

Seb O'Halloran was stabbed to death in Mildura in 2023.

A Mildura teenager claims his ex-girlfriend yelled “I told you I was crazy” moments after she plunged a kitchen knife into his mate’s chest.

Seb O’Halloran, 19, a talented motocross rider from Irymple in the state’s far northwest, was fatally stabbed after he was allegedly caught up in a fight between his friend and his friend’s girlfriend in a Mildura home in the early hours of October 21, 2023.

The girlfriend, who cannot be named because she was 17 at the time, is standing trial in the Supreme Court for the building apprentice’s murder, arguing self-defence.

Her ex-boyfriend, who witnessed the stabbing, was on Thursday the first witness called to give evidence, telling the jury an argument about breaking up led to his friend’s death.

The man, 19, admitted he cheated on his girlfriend which he said she found out about a week before the alleged murder.

While she was angry, he said they decided to stay together.

On the night of Mr O’Halloran’s death, the young couple met up with friends at The Corporate Moose pub but went separate ways after an argument.

Seb was remembered as a dearly loved son, brother, grandson and mate.

The boyfriend, who admitted dealing drugs, said his girlfriend hassled him throughout the night to give her cocaine.

“I kept saying no,” he told the court.

“I got sick of talking so I just gave it to her.”

CCTV footage showed the pair walking to an ATM before he went to a nightclub and she went to catch a taxi home.

She later went to the club and spoke to her boyfriend outside, where he claimed he told her he wanted to break-up with her before going back inside.

The girl and her friends went back to her home, where doorbell security footage recorded them berating the boyfriend.

“You wait c--t,” one girl says in the footage played to court.

“F--k you motherf--ker,” another says.

Still at the club, the boyfriend said he watched the footage on his phone before he enlisted his mate Mr O’Halloran to return home with him so he could break-up with her.

He said he discovered about $950 cash was missing from his stash before he confronted her.

“I walked up to her and said ‘I want my money, I want the keys to the house and I want you to pack your shit and leave’,” he said.

Seb was a talented motocross rider from Irymple.

His girlfriend tried to punch him before he grabbed her hands and pushed her to the ground and told her to stop, he said.

She was allegedly shoved into a room before she retrieved a kitchen knife and approached him.

“I heard big footsteps, like running, turn around, saw (her) with a knife in her hand,” the boyfriend said.

The boyfriend said he was standing near the doorway to his room while Mr O’Halloran was standing in a passageway on his phone.

She allegedly told Mr O’Halloran to move but he refused, telling her: “You’re not going anywhere near him.”

The boyfriend said she warned “I’ll do it” before plunging the blade into Mr O’Halloran’s chest before letting go and saying “I told you I was crazy”.

The boyfriend said he grabbed the girlfriend and threw her out the front door which was captured on doorbell footage played to court.

He then called triple-0.

“My girlfriend just f--king stabbed my mate,” he says in distressing audio played to court.

“He’s bleeding out everywhere.

“He’s like dying, please help.”

The court heard Mr O’Halloran stumbled into a dining room before he collapsed in a pool of blood and died.

Defence barrister Sharon Lacy SC earlier said the boyfriend and Mr O’Halloran were violent and her client acted in self-defence.

Under cross-examination, which began late on Thursday, the boyfriend denied raping the girl or treating her like a “piece of meat”.

His evidence will continue Friday.