A 15-year-old Adelaide schoolboy who allegedly possessed extremist material and coached others online about how to make bombs will be sentenced as an adult, meaning he could face up to 15 years in prison.
Prosecutors asked the Adelaide Youth Court to sentence the boy, who cannot be named for legal reasons, as an adult where a bigger penalty could be imposed.
Judge Penny Eldridge today allowed that application, which means he faces a maximum of 15 years' detention instead of three.
In her redacted judgement, Judge Eldridge said she agreed with prosecutors that the "gravity of the offending" meant he should be sentenced as an adult.
"The offences for which the youth has been charged are at the most serious end of the scale of criminality and the circumstances of them are extreme and of significant concern," she stated.
"The charges are clearly intended to intercept and prevent terrorist acts at an early stage."
Judge Eldridge redacted information from her judgement that outlined the precise allegations against the boy, before releasing it to the media.
The boy will reappear in the court in December where he is likely to plead guilty to possessing extremist material and taking steps to manufacture an explosive.
Prosecutor Aimee Winra previously told the court that the "gravity of the offending" meant the boy should be sentenced as an adult.
"This is not simply a case of a collection of a large volume of extremist material, which can only be categorised as extremely depraved and horrific in nature," Ms Winra said.
"The offending goes beyond that — there are active steps by the accused to provide guidance to others online on how to make explosives, suggesting he had a technical capacity to do so in pledging allegiance to the Bay'ah."
The concept of "Bay'ah" is to pledge allegiance to Islamic State.
Ms Wintra said detention centre staff also found drawings in his room of the Islamic State flag.
The boy's lawyer, Chris Weir, previously told Judge Eldridge that while his client would plead guilty to the crimes, further negotiations were needed to consolidate some of the counts before he officially entered his pleas.
"He's a young lad who was entrenched in his education and has a family who continues to support him," Mr Weir said.
He said the boy was receiving counselling in detention and taking part in a specialist program for children who are potentially radicalised.