Did the Assault Weapons Ban of 1994 Bring Down Mass Shootings? Here’s What the Data Tells Us

From 2004 Onward:
The data shows an almost immediate – and steep – rise in mass shooting deaths in the years after the assault weapons ban expired in 2004.

Breaking the data into absolute numbers, between 2004 and 2017 – the last year of our analysis – the average number of yearly deaths attributed to mass shootings was 25, compared with 5.3 during the 10-year tenure of the ban and 7.2 in the years leading up to the prohibition on assault weapons.

Saving Hundreds of lives
We calculated that the risk of a person in the U.S. dying in a mass shooting was 70% lower during the period in which the assault weapons ban was active. The proportion of overall gun homicides resulting from mass shootings was also down, with nine fewer mass-shooting-related fatalities per 10,000 shooting deaths.

Taking population trends into account, a model we created based on this data suggests that had the federal assault weapons ban been in place throughout the whole period of our study – that is, from 1981 through 2017 – it may have prevented 314 of the 448 mass shooting deaths that occurred during the years in which there was no ban.

And this almost certainly underestimates the total number of lives that could be saved. For our study, we chose only to include mass shooting incidents that were reported and agreed upon by all three of our selected data sources: the Los Angeles Times, Stanford University, and Mother Jones magazine.

Furthermore, for uniformity, we also chose to use the strict federal definition of an assault weapon – which may not include the entire spectrum of what many people may now consider to be assault weapons.

Cause or Correlation?
It is also important to note that our analysis cannot definitively say that the assault weapons ban of 1994 caused a decrease in mass shootings, nor that its expiration in 2004 resulted in the growth of deadly incidents in the years since.

Many additional factors may contribute to the shifting frequency of these shootings, such as changes in domestic violence rates, political extremism, psychiatric illness, firearm availability and a surge in sales, and the recent rise in hate groups.

Nonetheless, according to our study, President Biden’s claim that the rate of mass shootings during the period of the assault weapons ban “went down” only for it to rise again after the law was allowed to expire in 2004 holds true.

As the U.S. looks toward a solution to the country’s epidemic of mass shootings, it is difficult to say conclusively that reinstating the assault weapons ban would have a profound impact, especially given the growth in sales in the 18 years in which Americans have been allowed to purchase and stockpile such weapons. But given that many of the high-profile mass shooters in recent years purchased their weapons less than one year before committing their acts, the evidence suggests that it might.

Michael J. Klein is Clinical Assistant Professor of Surgery, New York University. This article is published courtesy of The Conversation.