The only way you can put forward any solutions is to spend time pouring over data and the studies completed, unfortunately people take a very simplistic and knee jerk approach with there solutions without doing the work thats required. USA is a very different beast to oz due to gun numbers per capita and demographics. One area often discussed in studies is the shelf life of guns being extremely long even with only moderate levels of care.
Motivations past violence how was weapon obtained? legally or illegally if illegally what was the failure point, point of sale at gun dealer, black market...
just to name a few of many factors that need to catorgorised accurately so if a solution is put forward it will work.
so if 95 out of 100 mass murders were due to illegal gun purchases, banning future purchases will have minimal effect.
What ever measures they put in it will take a bit to wash in for results, the clinton ban did reduce events but we are in different times so the data needs to be assesed to see if that would have an impact this time.
