Much of the debate over mass shootings has centered on the broader topics of gun ownership and gun purchase. This chapter details what is currently known and unknown about gun ownership in the U.S., including why individuals choose to own guns and the demographics of gun owners. While the focus is on adults, this chapter also touches on the reasons juveniles may opt to carry or possess guns. This chapter further addresses mass shootings by examining how mass shootings affect gun purchase and gun ownership patterns when they occur. The sources and types of guns used in mass shootings are also discussed. Lastly, the chapter highlights several efforts to restrict gun purchasing, all aimed at reducing the number of mass shootings that occur in the U.S. Throughout the chapter, specific, real-life examples are used to provide context for discussion. Examples of laws and policies at the state and federal level are provided as additional context.
TopIntroduction
On the evening of October 1st, 2017, more than 20,000 fans gathered to listen to Jason Aldean’s closing performance at the Route 91 Harvest Music Festival in Las Vega, Nevada (Blankstein, Williams, Elbaum, & Chuck, 2017). Shortly after 10pm, Stephen Paddock, age 64, started shooting into the crowd from the 32nd floor of the nearby Mandalay Bay hotel. A later investigation determined Paddock fired more than 1,100 rifle rounds, injuring more than 500 fans and killing 58. Paddock committed suicide just after the shooting. Police later found 24 firearms, an abundance of ammunition, and several high-capacity magazines in Paddock’s hotel room (Blankstein et al., 2017). As of this writing, this event remains the deadliest mass shooting in U.S. history (Berkowitz, Lu, & Alcantara, 2018).
Various sources define the term “mass shooting” based on casualties, injuries, and whether the event occurred in a single instance. The Federal Bureau of Investigation (FBI) now avoids the term and instead defines an active shooter as “an individual actively engaged in killing or attempting to kill people in a populated area” (2018). An active shooter is not necessarily a mass shooter; an active shooter could be intent on killing one or two people. The FBI designated 50 events as active shooter incidents across 2016 and 2017. The FBI defines “mass killings,” in contrast, as those events which result in three or more deaths (2018). Not all sources of crime data use these same cutoffs. MotherJones, a media source that tracks mass shootings, includes only incidents that result in four or more deaths (Pan, 2018). Some sources include the death of the offender, where applicable, towards the death total required by the definition (Everytown Research, 2018); others do not. Given these discrepancies in definitions used, counts of mass shootings in the U.S. vary. All definitions, however, hinge on an offender’s use of a firearm to injure or kill multiple individuals, typically in a public place.
This chapter explores this topic by focusing on firearms. Specifically, this chapter has the following objectives:
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Describe known trends in gun ownership in the United States
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Outline the laws that regulate gun ownership
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Explain why individuals own and purchase firearms
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Describe trends in gun purchasing before and after mass shootings
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Identify the guns most commonly used in mass shootings and where they originate
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Identify social movements and changes to gun-related law and policy that have resulted from mass shootings
Additionally, this chapter describes needs for future research.
TopGun Ownership
To better understand the role of firearms in mass shootings, it is helpful to examine gun ownership more broadly. Roughly one in every three U.S. adults personally owns a firearm (Parker, Horowitz, Igielnik, Oliphant, & Brown, 2017). In 2011, the Congressional Research Service estimated that there were 311 million civilian-owned guns in the U.S (Krouse, 2012). A more recent study from 2015 estimated the number of firearms at 265 million (Beckett, 2016). Others placed the 2015 count at more than 350 million (Ingraham, 2015) and the 2017 count at 393 million (Karp, 2018). Though these estimates vary, sources agree that the U.S. has the highest per capita civilian gun ownership rate in the world (Karp, 2018). Indeed, the U.S. had more than double the per capita gun ownership rate of any other country in 2017 (Karp, 2018). Gun ownership in the U.S. is also highly concentrated; roughly 3% of the nation’s gun owners own half or more of the nation’s guns (Beckett, 2016). Of gun owners in 2017, roughly 72% reported owning a handgun, 62% reported owning a rifle, and 52% reported owning a shotgun (Parker et al., 2017). Of those gun owners with only one firearm, 62% owned a handgun in 2017 (Parker et al., 2017).