Christchurch massacre 'inspired brothers'

The messaging app Telegram (file image)
The prosecutor says the terrorism case against two brothers includes encrypted posts via Telegram. -AP

Two white nationalists in NSW were inspired by the Christchurch massacre and the politics of hate, violence, and white supremacy to carry out their own terrorist attack, a jury has been told. 

Brothers Joshua and Benjamin Lucas are charged with preparing or planning for a terrorist act, with Joshua Lucas also charged with intentionally advocating for others to do a terrorist act.

The pair - now aged 23 and 25 - have pleaded not guilty in the Supreme Court in Parramatta after they were arrested in March 2020. 

Prosecutors allege the brothers had been plotting for a year and point to internet searches, social media posts and equipment purchases.

They also allegedly scoured potential targets and locations including mosques in Wollongong, synagogues on the NSW south coast and a defence facility near Jervis Bay.

But their defence lawyers say the young men were just having a bit of fun and provoking people online through "s***posting".

Chris O'Donnell SC in his closing address on Thursday said the case was made up of thousands of relevant circumstances including encrypted posts via the social media platform Telegram.

"Inspired initially perhaps by the Christchurch massacre and the politics of hate and violence and resentment and white supremacy underpinning that terrible event."

He said the evidence pointed to extreme white wing ideology and the pair had ultimately decided that Joshua Lucas would carry out the terrorist act. 

Video evidence played at the trial showed a very loud and powerful explosion set off among others in a remote location in July 2019. 

Joshua then allegedly shared this video on Telegram saying that it was his test without fuel.  

"That says a lot about his true intention. (He was) building improvised explosive devices, experimenting with them, testing with them, up to achieving a very significant success of creating that final device."

He disputed the suggestion this was simply joking around akin to setting off fireworks.

"A petty bunger or something to impress your friends is something I respectfully submit should be ultimately rejected by you in an overall assessment of the evidence."

Shortly after downloading and viewing the Christchurch massacre video, Joshua allegedly sought a munitions instruction manual handbook online. 

"It contained a whole lot of recipes and instructions regarding how to make explosive devices."

Mr O'Donnell submitted the online moniker JoshBro1488 had significant connotations to white supremacist ideology, the worship of Adolf Hitler, and the Christchurch murderer's "manifesto".

"It sends a message to people in the know."

Following his arrest police allegedly found a machete, six gel blaster guns, ammunition, packets of ball bearings, a balaclava and a Eureka flag.

The trial continues.