Parker's comments come after Prime Minister Jacinda Ardern's earlier remarks that New Zealand's gun laws would change.
Speaking to media in Wellington this morning, Ardern stressed that "now was the time for change.".
Ardern said five guns were used by the primary perpetrator, including two semi-automatic weapons, and two shotguns.
She said he had travelled around the world with "sporadic periods of time spent in New Zealand".
Despite this, the man was not on any watch lists in New Zealand or Australia.
Ardern said none of the arrested had a criminal history, either in New Zealand or in Australia.
A spokeswoman for the Prime Minister was not able to confirm which other ministers would be accompanying Ardern to Christchurch today. »