Video shows the moment the alleged Christchurch gunman was arrested.
The judge who presides over the case of the accused Christchurch gunman may invoke a rarely used order and hold the trial behind locked doors to protect "the security or defence of New Zealand".
The trial may also be held outside of Canterbury and potentially without any Muslim jurors, buta criminal justice expert says a carefully selected jury will ensure a fair trial.
Concerns were raised earlier this week when the Herald revealed accused mosque gunman Brenton Tarrant will represent himself in court, potentially turning his trial into a platform for his extreme beliefs - detailed in his manifesto.
However, the High Court judge who will preside over what will be an unprecedented trial will have a range of laws at their disposal to maintain order - one of which will could see the trial held behind locked doors, with even members of the press banned from attending.
An armed police officer stands guard outside Al Noor Mosque after 50 people were killed in the Christchurch attacks. Photo / Michael Craig
New Zealand's criminal justice system is generally open to the public, but under the Criminal Procedure Act any New Zealand judge has the power to clear their court.
This most often occurs in cases when a complainant gives evidence in cases of a sexual nature.
However, the judge has the ability to exclude people when it is necessary to avoid undue disruption to the proceedings.
Other reasons to close the court include; a real risk of prejudice to a fair trial, endangering the safety of any person, prejudicing the maintenance of the law - including the prevention, investigation and detection of offences - and when a suppression order is not sufficient to avoid that risk.
A judge can also clear the court if they believe it will avoid prejudicing the security or defence of New Zealand. This is also the only type of order which forces members of the media to leave a court.
Others allowed to remain in court regardless of any of the orders are the jury, prosecutor, defendant, lawyer engaged in the proceedings, officer of the court, and police officer in charge of the case.
But, even if the judge makes such an order, the announcement of the verdict and the passing of sentence must take place in public.
It can only be closed for verdict or sentence if the judge is satisfied that "exceptional circumstances exist".
The alleged Australian gunman's trial may also not be held in Christchurch.
A judge also has the power under the Criminal Procedure Act, by their own motion or on the application of the prosecutor or defendant, to transfer the proceedings to a different place.
A transfer is permitted if the judge "is satisfied that it is in the interests of justice that the proceeding be heard at that other place or sitting".
Criminal justice associate professor at the Auckland University of Technology Khylee Quince said other trials have been moved in the past - including David Bain's first murder trial.
"One of the concerns is that you can't find 12 people who are going to act impartially in relation to an event that's happened in their community," she said.
The accused gunman has indicated he will represent himself during the trial. Photo / Mark Mitchell
A decision to move a trial elsewhere would often rely on if a jury could be found which did not have knowledge of the case. But in today's digital age, where almost every New Zealander is aware of the Christchurch terror attacks, that would not be such a strong basis for a transfer, Quince said.
"What might make this a little bit different, though, is just the sheer scale and size and, you know, the fact that this is such a large scale harm.
"Even if the jury pool hadn't been directly affected by the shooting, they could have an emotional and psychological connection to the harm," Quince added.
"All New Zealanders and I would think all human beings would be affected by having to filter through and listen to evidence of harm of this scale."
The judge also has further powers to direct the trial be held before them-alone rather than 12 lay New Zealanders.
This can be ordered in cases involving the intimidation of a juror or jurors.
Under the Criminal Procedure Act, however, the judge must be satisfied there are reasonable grounds to believe that intimidation of any person or persons who may be selected as a juror or jurors has occurred, is occurring, or may occur; and that the effects of that intimidation can be avoided effectively only by making the order.
But Quince said it was unlikely the trial could be converted to be heard by a judge-alone, as the risk of intimidation must be direct and personal. She had never heard of a murder case being heard as a judge-alone trial.
If the accused gunman continues to defend himself, it is also likely the court will appoint an amicus curiae - a friend of the court - at the trial.
The alleged gunman's bullet-riddled car is seized by police as evidence. Photo / Claire Chambers
An amicus is a lawyer who is not a party to the case but assists the court and advises the defendant on the rules and how conduct his defence properly.
This means it is also likely witnesses who could be traumatised by having to be cross-examined can instead be questioned by the amicus, Quince said.
They could also give evidence via closed circuit television to avoid seeing the defendant.
Quince said there were several measures the court could take to ensure the defendant had the fairest trial possible under the circumstances - much of which would come down to carefully selecting the jury.
Lawyers can challenge a juror without reason up to six times during the empanelling process, and can make additional challenges based on legitimate reasons such as whether the person has a criminal conviction or whether they know the accused.
Quince was curious to know whether any Muslim people would be allowed on to the jury.
"They are citizens of this country, they're entitled to be considered," she said.
The alleged killer is currently facing one charge of murder, but is likely to face more, following the deaths of 50 people in last Friday's attacks at the Al Noor Mosque and the Linwood Islamic Centre.
Fifty more people were wounded.
The 28-year-old accused was remanded in custody, understood to be at New Zealand's only maximum security prison in Paremoremo, until his first High Court appearance on April 5.
