A radicalised teenager who was arrested at a Muslim prayer hall after buying two bayonets to use in an imminent Sydney terrorist attack has been jailed for at least 12 years.
The then 16-year-old shouted at the arresting police: "You're all pigs ... look at you, like lambs to the slaughter ... you will all die in the hellfire at the hands of Allah ... you will be slaughtered at the hands of Allah."
He was sentenced in December 2018, but details could not be reported until the conclusion of his school friend's retrial in the NSW Supreme Court.
The original jury which had found the teenager guilty could not reach a verdict on the friend, but on Tuesday another jury found him guilty.
He will be back in court on May 1.
Both teenagers, now 19, had pleaded not guilty to doing an act or acts between October 6 and October 12 in 2016 in preparation for a terrorist act.
They were 16 when arrested at the prayer hall in Bankstown in October 2016.
In sentencing the first teenager to 16 years with a non-parole period of 12 years, Justice Geoffrey Bellew concluded he had been "an unequivocally committed terrorist".
He was only 12 when filmed at a Sydney CBD protest holding a large poster stating "Behead all those who insult the prophet".
Two years later, he refused to stand for the national anthem at a school assembly, saying he "did not stand for anybody except Allah".
He was found to have possessed extremist material advocating violence with instructions as to how a terrorist attack could be carried out using knives.
In October 2016, while his friend waited outside, he entered the Bankstown Gun Shop and paid $230 for two M-9 Bayonet knives and a knife sharpener.
They previously bought two hunting knives with one youth telling the shop assistant they were going pig hunting.
Contrary to the teenager's evidence at his sentence hearing, Justice Bellew found that at the time of arrest "the perpetration of a terrorist act involving the infliction of harm with the use of a knife was imminent".
The teenager had testified to regarding the government as "evil".
"The nearby presence of the (Bankstown) police station and court house, both of which represented arms of government, meant that the offender would inevitably have found many persons within the immediate vicinity who he regarded as appropriate targets."
While acknowledging the youth was only 16 at the time, the judge said he was unable to accept any suggestion of naivety, immaturity or lack of intelligence.
The action he took in order to carry out an attack reflected a "considerable degree of forethought, intelligence and guile".
"It also reflects a deep and unstinting motivation to act upon, and put into specific effect, the irrational, immoral and heinous advice propounded in extremist propaganda issued by Islamic State."
The teenager's declaration that he would not revert to his previously held extremist ideology must be approached with considerable caution, the judge said.
Putting it at its highest, the evidence may suggest the teenager was making "tentative steps" to move away from those views.