Rampaging teens 8 months detention

Three of the five teenage boys who went on a rampage through a western Sydney school could be released from juvenile detention by Christmas.

Eighteen students and staff were injured when the teenagers entered Merrylands High during school assembly, armed with baseball bats, a machete and a sword.

The magistrate, Sharon Holdsworth, said premeditation was involved because the boys planned the event, catching a bus to school with their weapons and intending to target one of the students in a revenge attack.

So far, three of the boys have been given the same sentence of 12 months in juvenile detention with a non-parole period of eight months.

That makes them eligible for release before Christmas.

The court heard the boys often skipped class but had never been in trouble with the police before, although two had been caught with knives at school.