The teen's rap sheet, much of which occurred in the last six to 12 months, was aired in a children's court as he tried to apply for bail on Wednesday.
He is charged with intentionally causing serious injury, assault with a weapon, possessing a controlled weapon and armed robbery after he allegedly attacked a 39-year-old man while trying to steal his car in St Kilda on January 12.Â
The boy, who has an intellectual disability and autism, allegedly pulled a machete from his pants and slashed the man across his skull leaving him bleeding with a 10cm wound, the court was told.
A detective said the boy, who lives in regional Victoria, posed "a significant risk to the public and his offending is showing no signs of slowing down".
"He is quite well known in the youth crime community, he has a lot of notoriety about him, people want to latch onto his offending," Detective Senior Constable Timothy Paltridge told the court.
The teen was on four different sets of bail when he allegedly committed what the detective described as a "vicious and callous" attack.
He detailed the boy's previous 12 months of offending, including allegedly bringing a 40cm hunting knife to school because he told staff he needed it for "protection".
He is also accused of slashing another person with a machete in a group assault, putting a nurse into a headlock after trying to steal her car as she finished night shift, car thefts and speeding up to 180km/h before a crash, the detective said.
Det Sen Const Paltridge said the boy had "flouted every single bail condition" he'd been given previously, including a social media ban, curfew and visiting Melbourne.
"He's been given countless opportunities," he said.
"(The teen) will continue to put the lives of members of the public at risk to get what he wants."
The boy's defence lawyer asked for the bail application to be adjourned because his mother said she was not "willing or able" to have the teen to reside with her.
She further told the court that Youth Justice had found he was not suitable for bail.
The magistrate said it will be difficult for defence to prove the boy was not an unacceptable risk to the community, as he had already been given chances on bail.
"There are a lot of issues that still need to be addressed, and here the risk has materialised," he said.
But he accepted the teen's disabilities would make him more vulnerable both in custody and within the community.
The teen was taken back to youth detention and will return to court on February 3.
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Kids Helpline 1800 55 1800 (for people aged 5 to 25)
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