No knives out here, just a reasoned response. Any new demand would be touted as "a good first step", with the undeclared last step being confiscation.
As outlined by others, the system works IF the authorities keep the proscribed list up to date, which they didn't do in this and other cases.
Please review the gun buying application we here in the States have to fill out when buying from a licensed dealer and tell us what changes you would make to it to preclude further tragedies like this. (Note that this is an obsolete form (2005) and a change regarding race has been made. Also note that a photo ID must be submitted to the dealer.): 
and 
Note Section D in the second form. This is why "Universal Background Check" (mandatory for all private, non-FFL sales) is pushed by the liberals. With that info they would know who has what and where they are - must needs for Universal Confiscation.