There are fears terror suspect Brenton Tarrant will use his appearances in court to spread his "spout his vitriol and worldview".
Massey University law professor Chris Gallivan told The AM Show the similarities between the Christchurch attack and Anders Breivik's rampage in 2011 are "disturbing".
A self-described Nazi, Breivik killed eight people with a bomb in Oslo in July 2011, before heading to a youth camp and killing 69 more.
On the first day of his trial, Breivik gave a Nazi salute. Over the next few weeks, Breivik would go on to explain his ideology and try to justify his atrocious actions, pleading not guilty because he felt it was necessary to carry out "a small barbarian act to prevent a larger barbarian act".
Gallivan fears Tarrant will do the same, if he pleads not guilty.
"We're going to hear a lot more about this gentleman and probably from this gentleman, and also about his ideology, before this is over," he told The AM Show on Monday morning.
"We have to ensure the victims are protected through that and that it is not a platform to be able to extol his worldview. But if he self-represents - the courts probably will struggle to stop him using this as a platform.
"Anders Breivik didn't recognise the jurisdiction of the court and used every opportunity he possibly could to spout his vitriol and worldview."
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Gallivan said in his classes he often talks about one of the survivors of Breivik's massacre in 2011.
"He said - quite wisely for a victim - 'Look - all I care is there is a fair trial and that justice is actually served and the process is a fair and just one - but he not be given a platform to extol his vitriol.'"
On the other hand, Gallivan says it could be "cathartic" for the country "for [the] perversity of his worldview to be exposed for what it actually is".
Tarrant is expected to next appear in court in early April. Police say a number of charges will be laid.
As for what punishment he'll face, Gallivan says there is no local precedent, with the Breivik trial being the most similar overseas incident.
"We have Aramoana and David Gray, but he was shot and killed. In the past where there has actually been mass atrocities, that have been nowhere near the scale as we've seen here, there has not actually been a trial at all."