A former security adviser to US President Ronald Reagan says the Christchurch terrorist would likely have been picked up before the March 15 attack if it was America, but that's because 9/11 led to big changes in American systems.
Lawrence Korb says gunman Brenton Tarrant's online action alone would have raised a red flag in the US.
"The social media would have done it, the fact that he was getting a gun," he told Newshub.
He says it's highly likely the terrorist would have been picked up there - before this deadly massacre. He says 9/11 was the catalyst for a security overhaul.
"As I read your [Royal] Commission's report, it reminds me very much of the one we had after 9/11."
But it took 19 years and one of the world's worst terrorist attacks for New Zealand to do something similar.
Korb also says that whilst the US hides behind its constitutional right to bear arms - New Zealand's gun laws should have been tighter.
"You don't have that in your constitution so I think you can make it very hard for people to get guns and make sure you do a background check."
One of the things that have most upset March 15 victims are New Zealand authorities were looking in the wrong direction. In the mosque attack Royal Commission of Inquiry findings released on Tuesday, it talks of a computer accessing extreme far-right and suspicious firearms material the year before the Christchurch terrorist attack, but the Security Service deemed it low priority and closed the lead.
They now know several things that could link it to Tarrant.
Security on this side of the world is changing fast. On Wednesday night, an 18-year-old Sydney man was arrested after his far-right online activity.
There was no imminent threat and no specific plot - police acted because of his behaviour online, including his expression of admiration for the Christchurch gunman.
Victims want March 15 to teach Governments here and around the world a firm lesson.
"Something like this can happen anywhere, and we should be prepared for it," says victim Abdul Aziz.
