The 17-year-old charged over an alleged school massacre plot at Riverland School will be tried as an adult.
The boy, who was 16 when arrested, has been charged with solicit to murder as a consequence of the plot.
During an appearance in Youth Court on Wednesday, the prosecutor Tegan Mullan said that the charges would be refiled in the Adelaide Magistrates Court, where he will be tried as an adult.
A 19-year-old man has been co-accused and charged with solicit to murder, as well as four aggravated counts of threatening to kill.
Both boys are in custody and are yet to enter pleas to the charges.
The maximum penalty of solicit to murder is life imprisonment.