INMATES at Acmena Juvenile Detention Centre taunted staff with threats to rape their wives and children during a violent outbreak at the centre last month.
At a Children's Court hearing at Grafton earlier this week, police gave evidence of inmates throwing pool acid at staff and threatening staff during the confrontation on October 21.
Police said the trouble began when a detainee was being moved to a confinement room for bad behaviour and broke free of his escorts.
"The detainee broke free from the escort and ran towards a fence and perched himself on top," said police.
From there he began abusing and threatening the staff and saying he would rape their wives, families and kids.
He is also alleged to have said he would kidnap the staff's children and tie them up.
Four other detainees who were in the pool area at the time joined in and kicked in the door to the pool's pump shed.
It's alleged they returned with a fire extinguisher and fired it at staff, while passing metal poles through the fence to the boy who had fled his escort.
While the first boy was wielding the poles in the direction of staff and saying he would kill them if they came any closer, the others are alleged to have thrown a garden hose over the fence so they could all be in the same yard.
The five of them then went on what the police described as a "destructive rampage", knocking doors off hinges and throwing them in the pool.
"The young persons gained access to the containment shed and gathered tools, metal objects and other items and either damaged them or used them as weapons to threaten staff," police said.
"Pool acid was used to threaten staff and some was thrown at them.
"Metal poles were manufactured with blades attached them and also used to threaten staff."
It is also alleged the detainees threw broken bricks and cement at staff and security cameras throughout the incident.
The police report found the staff were going about their normal duties and the detainees had no reason to act the way they did.
The first of the accused pleaded guilty to affray, assaulting an officer of the law, being armed with intent to commit an indictable offence, and destroying property in Grafton Children's Court on Monday.
He was sentenced to two years' juvenile detention with a non-parole period of 12 months.
A spokeswoman from the Department of Juvenile Justice said all five of the detainees involved in the incident have been moved to another facility.