A high-profile security expert has questioned whether the Government has chosen the right people to lead the probe into how the Christchurch attack was able to happen.
The Royal Commission into the attack on two Christchurch mosques will be headed by Supreme Court Justice Sir William Young and former diplomat Jacqui Caine.
It will look at the alleged shooter's use of social media, his arrival and residence in New Zealand, how he got a firearms licence, what agencies knew before the attack and how they responded.
Paul Buchanan, a former university professor and presently director of geopolitical consultants 36th Parallel Assessments, told The AM Show on Monday they might not be the right people.
"Obviously Sir William Young is an accomplished jurist and Jacqui Caine is a good diplomat, but what makes them have unique qualifications to be the commissioners for this royal commission? Neither one has a background in counter-terrorism.
"Why do we always have a former High Court judge? Does it mean they have integrity and can keep a secret? Okay, fine. But it doesn't mean that they know about the terrorism business."
When Sir William was appointed chair, Prime Minister Jacinda Ardern said he "has the extensive experience and skills required to lead the inquiry".
"I am confident that in his nearly nine years as a judge on our highest bench, Justice Young has the judgement, clarity and care to do the job, with a sound understanding of intelligence issues and experience working in the public eye."
On Sunday after Caine's appointment, Ardern said she was confident the right people were in place.
"This is a critical part of our ongoing response to the attack. The commission's findings will help to ensure such an attack never happens here again."
The commission will have two main parts to it, he said - one easy, one hard. The former is the investigation into the "mechanics of the crime".
"How he prepared, how he planned, whether he had accomplices."
The second will be looking at the "individual, institutional and systemic failures that facilitated the crime", and then taking real action to fix them.
"We've got to adjudicate responsibility. I'm really hoping that this royal commission is transparent and holds people accountable. You cannot blame the lowest guy on the totem pole. I can see now a scenario where an individual gets scapegoated and the higher-ups walk free... If there's institutional and systemic failures, it has to start at the top."
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To do that, Dr Buchanan said someone from overseas should have been brought in to handle the inquiry.
"You've got to get out of the New Zealand mindset if you want to truly be independent and objective... it's hard to examine yourself."
Dr Buchanan also expressed concern the agencies that failed to pick up the alleged killer beforehand will get to dictate some of the terms Sir William and Caine will have to work under.