Mass Shootings Facts and Fiction

Let’s start by clarifying terms and definitions. There are a couple of common definitions for mass shootings, and they are very different…
Mass Shootings (MS) include multiple-victim shooting incidents that occur in connection with some other crime. These may include felony-related shootings where both the victims and offenders may be involved in unlawful activities, such as organized crime, gang activity and drug deals. Domestic disputes are incidents where the majority of victims are members of the offender’s family, not random victims as are associated with mass public shootings. Depending how the MS data is sliced, events associated with domestic violence and criminal activity make up 80 to 88 percent of mass shooting incidents in the U.S. with four or more fatally injured victims (Krouse, William J. and Daniel J. Richardson, Mass Murder with Firearms: Incidents and Victims, 1999–2013, Washington, D.C.: Congressional Research Service, R44126, 2015.).
U.S. deaths due to mass shootings is less than 0.1% of total from 1995-2016

Mass Public Shootings (MPS) are most commonly defined as follows: 

  • The Federal Bureau of Investigation (FBI) defines a mass murderer as someone who kills four or more people in a single incident (not including himself) with no “cooling-off period” between the murders, typically in a single location.
  • In 2013, the U.S. Congress defined public shooting events as incidents where three or more people are killed.
In the U.S., mass public shootings account for less than 0.5% of all gun deaths every year.

However, there isn’t yet a universally accepted definition of the term. So academic researchers, various media outlets, government organizations (e.g., the Centers for Disease Control, U.S. Department of Education), advocacy groups (e.g., Everytown for Gun Safety), other entities (e.g.,’s Mass Shootings Tracker) and law enforcement agencies frequently use different definitions when discussing mass public shootings. This can lead to biased statistics and complicates our understanding of mass public shooting trends and the relationship to gun policy.

"We should ban assault rifles and high-capacity magazines to stop mass shootings."


Between 1988 (when officials began documenting detailed information) and August 4, 2019, assault rifles were used in only 14 percent of those events.

Assault Rifles

Although the 1994 Federal Assault Weapons Ban expired on September 13, 2004, in accordance with its sunset provision, the definition provides a basis for identifying how many mass public shooters used this type of firearm. That definition of “semi-automatic weapon” included specific semi-automatic firearm models by name, and other semi-automatic firearms that possessed two or more certain features. Based on the MPS Database, assault rifles were used in approximately 14 percent of those events.

High-Capacity Magazines

Per the Heritage Foundation website, noted in The Current Gun Debate: Mass Shootings (March 2018), “Few mass public shooters have used high-capacity magazines, and there is no evidence that the lethality of such attacks would have been affected by delays of two to four seconds to switch magazines. In fact, some of the largest mass shootings in U.S. history were carried out with low-capacity weapons:
  • The Virginia Tech shooter killed 32 and injured 17 with two handguns, one of which had a 10-round magazine and the other a 15-round magazine. He simply brought 19 extra magazines.
  • Twenty-three people were killed and another 20 injured in a Killeen, Texas, cafeteria by a man with two 9mm handguns, capable of maximums of 15-round and 17-round magazines, respectively.
  • A mentally disturbed man armed with two handguns and a shotgun shot and killed 21 people in a San Ysidro McDonald’s and injured another 19. The handguns utilized 13-round and 20-round magazines, and the shotgun had a five-round capacity.

Although mass public shootings account for only 0.1 percent of the total firearm-related mortality between 2000 and 2014, they bring national attention to the issue of firearm violence. Then a familiar series of events follow: First, there is a discussion of how that particular event could have been prevented, followed by a public outcry that stricter gun laws are needed. In actuality, existing laws that, if followed, may have prevented the event in question, are often not enforced.

In March, based on Michael Siegel Claire Boine’s article entitled “What Are The Most Effective Policies In Reducing Gun Homicides?”, knee-jerk reactions rooted in emotion will not solve the problem. To date, evidence shows that the problem requires solutions that are versatile and grounded in evidence. Analysis shows no significant association between homicide rates and assault weapons bans, large-capacity ammunition magazine bans, one-gun-per-month laws, “stand your ground” laws or prohibitions on gun trafficking.

The findings suggest that laws which regulate the “what” (i.e., what guns/products are allowed) do not have much of an impact on overall population homicide. In contrast, laws that regulate the “who” (i.e., who has legal access to firearms) may have an appreciable impact on firearm homicide, especially if access is restricted specifically to those people who are at the greatest risk of violence: Namely, people who have a history of violence or represent an imminent threat of violence.

“The U.S. accounts for more than 30 percent of mass public shootings compared to other developed countries."


While the U.S. population is 4.6 percent of the world total, only 1.43 percent of mass public shooters were American.

Worldwide Comparison

Although you may see sensational headlines to the contrary, when compared with other developed countries and accounting for population differences through the 47 years from 1966 to 2012, the U.S. makes up less than 1.43 percent of the mass public shooters population. It also accounts for 2.11 percent of attackers’ murders and 2.88 percent of the attacks. All these are much less than the U.S.’s 4.6 percent share of the world population. Attacks are not only less frequent in America than in other countries, they are also much less deadly on average. The 437-page data set and detailed list of countries can be found on the CPRC website.

Deadly Acts of Terrorism

Also documented by the Heritage Foundation, bombings, mass stabbings and car attacks frequently kill more people in foreign countries than even the deadliest mass shootings in the United States. Consider the following:

More Statistics to Consider

  • Mass killings are very rare, accounting for only 0.2 percent of homicides every year and approximately 1 percent of homicide victims.
  • Only 12 percent of mass killings are mass public shootings. Most mass killings are “familicides” (murders of family members or intimate partners) and felony-related killings (robberies or gang-related “turf battles”).
  • Per the Pew Research Center, gun murder and suicide rates in the U.S. are both lower today than in the 1970s. There were 4.6 gun murders per 100,000 people in 2017, far below the 6.2 recorded in 1976. And the rate of gun suicides – 6.9 per 100,000 people in 2017 –  remains below the 7.7 per 100,000 measured in 1977.

"Mass shooters tend to choose so-called ‘gun-free zones’ for their attacks."​


From 1988 through August of 2019, more than 85 percent of Mass Public Shootings have occurred in gun-free zones.

Cattle Pen Trend

Using the MPS Database, which contains the 71 MPS (using the FBI definition) documented in the U.S. between 1988  and August 4, 2019, more than 85 percent of MPS have been perpetrated in gun-free zones. (Although the data set goes back to 1982, detailed information began to be documented in 1988.) These gun-free zones include 17 workplaces, 12 schools, five churches and three shopping malls.

As reported by, in addition to gun-free zones, some MPS with the highest fatalities have another common factor. Defined by, they occurred in “cattle pen” scenarios:
  • Many people in a “crowded” area (required); and
  • Limited exits or exit capacity; and/or
  • Few or no places to take cover.

Shooters research locations where they can pen in large numbers of potential victims, giving them the potential for a higher body count. In those situations, marksmanship becomes less relevant or even irrelevant. Simply firing into the crowd will result in deaths.

Upon reviewing MPS data, GunFacts observed certain years showed dramatically large spikes in terms of the number of victims of such attacks. They noted, “the most prominent of the spikes were the years of the Virginia Tech, Sandy Hook, Pulse Nightclub, Las Vegas music festival and Sutherland Springs church shootings. The average number of fatalities of those events is 5.4 times larger than the average for all other events in the 21st century.”

“My Gun Was 100 Yards Away”

Suzanna Gratia Hupp, formerly a Texas House representative for 10 years, survived a cattle pen scenario at Luby’s in Killeen, TX in 1991, which resulted in the deaths of 23 people, including both of her parents. With the firm belief she could have saved the lives of many or all of the 23 victims if gun control laws had been more lax, Hupp has lobbied for less firearm restrictions for decades.  “I reached for the gun in my purse on the floor next to me,” she told a congressional committee during a hearing on the economic costs of gun violence. Hupp recounted the moments after the killer crashed his pickup into the restaurant where she was eating with her parents and opened fire. “But then I realized that a few months earlier I had made the stupidest decision of my life. My gun was 100 yards away, dutifully left in my car to obey the law because at that time, in the state of Texas, carrying a handgun was illegal.”