Since Semi-Automatic Rifles Outlawed, Australia Has Had Zero Mass Shootings Interview with:

Simon Chapman AO PhD FASSA Hon FFPH (UK) Emeritus Professor in the School Public Health University of Sydney

Prof. Chapman

Simon Chapman AO PhD FASSA Hon FFPH (UK)
Emeritus Professor in the School Public Health
University of Sydney What is the background for this study?

Response: Since major gun law reforms in 1996, Australian has seen zero mass shootings (five or more deaths, not including the perpetrator).The law reforms outlawed semi-automatic rifles, those often favored by mass killers.

In the 18 years prior to the reforms, Australia experienced 13 mass shootings. The National Rifle Association and others have suggested that the 22 year absence of mass shootings may simply reflect that these events are rare and statistically unlikely to occur regardless of any policy. What are the main findings? 

Response: We mathematically calculated the probability that 18 years with 13 massacres would be followed by 22 year with none. The likelihood of this occurring is about 200,000 to one – lower than the odds of winning first prize in a major Australian lottery. We estimated that the law reforms averted a likely 16 mass killings from occurring in Australia, had the previous trend continued. What should readers take away from your report?

Response: The probability that mass shootings have stopped because they are simply “rare events” is infinitesimally small. The obvious conclusion is that the gun law reforms were associated with the 22 year halt in gun massacres in Australia. 

Disclosures: Professor Simon Chapman was involved in the Coalition for Gun Control which advocated gun law reform from 1993-1996 (22 years ago) 


Simon Chapman, Michael Stewart, Philip Alpers, Michael Jones. Fatal Firearm Incidents Before and After Australia’s 1996 National Firearms Agreement Banning Semiautomatic Rifles. Annals of Internal Medicine, 2018; DOI: 10.7326/M18-0503 

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