A teenager accused of plotting a school massacre in the South Australian Riverland has been refused bail, as allegations were aired in court that he previously took "dirty great big knives" and Molotov cocktails to school.
The 19-year-old man and a 17-year-old boy, whose identities have been suppressed, were charged with conspiring to murder over an alleged plot to attack the school with guns and explosives last year.
Prosecutors alleged the pair persuaded each other to commit mass murder and they intended to kill as many people as possible in the attack.
It was alleged the younger teen took steps to obtain guns, knives, Molotov cocktails and materials to make pipe bombs.
In opposing the 19-year-old's release on home detention bail, prosecutor Jim Pearce told the Adelaide Magistrates Court there had been "escalation of activity" by the teenagers in late October when they started making Molotov cocktails and threw one at the school's fence during Halloween.
"The fact remains that there wasn't just talk about Molotov cocktails, there was manufacture, and indeed there is discussion about that in Facebook Messenger exchanges," he said.
Mr Pearce said there were also photographs showing knives the teenagers had brought to school.
"They've got a couple of really dirty great big knives thrust into the table at the school," he said.
Defence cites 'massacre fantasies'
The 19-year-old's lawyer, Stephen Ey, told the court the community would not be at risk if his client was released on home detention bail because he had been telling people about his school massacre "fantasies" for years.
"The likelihood of him acting on these thoughts is extremely remote," he said.
"For almost years, as I understand it, he has been making throwaway utterances that people have never taken seriously."
"The proof is in the pudding [that] for this lengthy period of time nothing has ever happened."
But Mr Pearce called for community protection to be the court's paramount concern.
He said there had been a "high level of anxiety" felt among staff at the school since the allegations surfaced.
"The school received hundreds of calls at the relevant time from parents ... so many calls were received about what was going on, they had to divert the phones to down here in the city," Mr Pearce said.
The court heard a social worker and psychologist had to be brought in to assist staff and students.
Magistrate Greg Fisher said he appreciated the effect on the community and refused to grant the 19-year-old home detention bail.
"If the defendant was to be released back into the community it would cause the alleged victims to have concern about their physical protection," he said.
The matter returns to court later in the month.
