De Leo, Dwyer, Firman & Neulinger,
studied suicide methods in men from 1979 to 1998 and found a rise in hanging suicides that started slightly before the fall in gun suicides. As hanging suicides rose at about the same rate as gun suicides fell, it is possible that there was some substitution of suicide methods.
It has been noted that drawing strong conclusions about possible impacts of gun laws on suicides is challenging, because a number of suicide prevention programs were implemented from the mid-1990s onwards, and non-firearm suicides also began falling.
In 2005 the head of the New South Wales Bureau of Crime Statistics and Research, Don Weatherburn, noted that the level of legal gun ownership in New South Wales increased in recent years, and that the 1996 legislation had had little to no effect on violence
. Professor Simon Chapman
, former co-convenor of the Coalition for Gun Control, complained that his words "will henceforth be cited by every gun-lusting lobby group throughout the world in their perverse efforts to stall reforms that could save thousands of lives". Weatherburn responded, "The fact is that the introduction of those laws did not result in any acceleration of the downward trend in gun homicide. They may have reduced the risk of mass shootings but we cannot be sure because no one has done the rigorous statistical work required to verify this possibility. It is always unpleasant to acknowledge facts that are inconsistent with your own point of view. But I thought that was what distinguished science from popular prejudice."
In 2006, the lack of a measurable effect from the 1996 firearms legislation was reported in the British Journal of Criminology.
Using ARIMA analysis, Dr Jeanine Baker (a former state president of the SSAA(SA)) and Dr Samara McPhedran (Women in Shooting and Hunting) found no evidence for an impact of the laws on homicide.
Subsequently, a study by McPhedran and Baker compared the incidence of mass shootings in Australian and New Zealand.
Data were standardised to a rate per 100,000 people, to control for differences in population size between the countries and mass shootings before and after 1996/1997 were compared between countries. That study found that in the period 1980–1996, both countries experienced mass shootings. The rate did not differ significantly between countries. However since 1996/1997, neither country has experienced a mass shooting event despite the continued availability of semi-automatic longarms in New Zealand. The authors conclude that “the hypothesis that Australia’s prohibition of certain types of firearms explains the absence of mass shootings in that country since 1996 does not appear to be supported…
if civilian access to certain types of firearms explained the occurrence of mass shootings in Australia (and conversely, if prohibiting such firearms explains the absence of mass shootings), then New Zealand (a country that still allows the ownership of such firearms) would have continued to experience mass shooting events.”