Mass Shootings in the United States: 2009-2017

December 6, 2018

Using media reports and official records, Everytown for Gun Safety develops an annual analysis of mass shootings in the United States. This report includes mass shootings that took place between January 2009 and December 2017.


“I thought it was firecrackers at first, and when those bullet holes started coming through the door, it was obvious it wasn’t. I stood up and I was hollering for people to get down on the floor, get on the floor, and one caught me in the forearm and actually threw me down on the floor. As I laid there, what was going through my mind is, ‘it doesn’t seem to stop, it just keeps going on and on.’”Spriester S, Medina M. 700 rounds in 11 minutes: Sutherland Springs survivor says he’s amazed he’s alive. KSAT. February 5, 2018.

Sutherland Springs, TX

This is a description from a survivor of the November 5, 2017 mass shooting at First Baptist Church in Sutherland Springs, TX. In less than 10 minutes, the shooter fired hundreds of rounds of ammunition from outside and inside the church,Spriester S, Medina M. 700 rounds in 11 minutes: Sutherland Springs survivor says he’s amazed he’s alive. KSAT. February 5, 2018. killing 25 people and an unborn baby and injuring 20 more.Goldman A, Pérez-Peña R, Fernandez M. Texas church shooting video shows gunman’s methodical attack, official says. New York Times. November 8, 2017. A video camera in the church – intended to record services for the church’s YouTube pageGarcia A. A look inside Sutherland Springs’ First Baptist Church before mass shooting. KSAT. November 5, 20177. – captured the shooter walking up and down the center aisle, firing into each row of pews where victims tried to hide.Briscoe M, Shah B. Texas church gunman walked up and down aisles, shooting as people crawled out of pews. The Daily Beast. November 6, 2017. By the time the gunfire ended, it became the deadliest mass shooting in modern Texas history, and one of the five deadliest mass shootings in modern U.S. history.CNN Library. Deadliest mass shootings in modern US history fast facts. CNN. Last updated May 23, 2018. Accessed October 8, 2018.

When it comes to mass shootings in the U.S. – incidents in which four or more people are shot and killed, not including the shooter – the shooting at First Baptist Church fits many familiar patterns.

First, the shooter was prohibited from purchasing or possessing a firearm. In 2012, while serving in the U.S. Air Force in New Mexico, the shooter was charged with numerous assaults, including for threatening his ex-wife with a loaded gun. He ultimately was convicted of striking and choking his ex-wife, and for striking his infant stepson so hard he fractured his skull.General Court-Martial Order No. 10 for Airman First Class Devin P. Kelley. Department of the Air Force, Headquarters Twelfth Air Force, Davis-Monthan Air Force Base, January 14, 2013.,Blinder A, Philipps D, Oppel RA. In 2012 assault, Texas gunman broke skull of infant stepson. New York Times. November 6, 2017. These convictions should have prohibited him from purchasing and possessing firearms, but the Air Force did not properly relay the record of his conviction to the federal background check database system.Montgomery D, Oppel RA, Del Real JA. Air Force error allowed Texas gunman to buy weapons. New York Times. November 6, 2017.

Second, there were several other warning signs that the shooter posed a dangerous risk. According to law enforcement, his social media posts indicated an interest in both mass shootings and assault rifles.Grinberg E, McLaughlin EC. Texas church shooter Devin Patrick Kelley’s troubled past emerges. CNN. November 8, 2017.,Id. And, in the week before the shooting, a neighbor of the shooter in New Braunfels, TX reported hearing bursts of rapid gunfire from his property every morning: “A load of rounds that would always be going off [at] this time…I was concerned because it was so close to our house.”Id.

Third, in addition to the shooter having a history of domestic violence, he appears to have targeted his wife’s family in the attack. After remarrying in 2014, investigators claim he sent threatening text messages to his mother-in-law in the lead up to the shooting and may have targeted First Baptist Church because it was her place of worship.Yan H, Stapleton A, Simon D. Authorities: Texas church shooter had three gunshot wounds. CNN. November 7, 2017.,Siemaszko C, Johnson A. Texas church shooter had ‘a purpose and a mission’ in family feud, investigator says. NBC News. November 6, 2017. His mother-in-law was not in the church at the time of the shooting, but his grandmother-in-law was. She was one of the 25 victims shot and killed.Yan H, Stapleton A, Simon D. Authorities: Texas church shooter had three gunshot wounds. CNN. November 7, 2017.

Finally, the shooter was armed with a semi-automatic rifle that was equipped with high-capacity magazines. In fact, investigators found 15 empty magazines in the church, each capable of holding 30 bullets.Hanna J, Yan H. Sutherland Springs church shooting: What we know. CNN. November 7, 2017. This suggests that the shooter fired at least 450 rounds during the attack.

Executive Summary

Mass Shootings in the United States is an annual report published by Everytown for Gun Safety to better assess the reality of mass shootings in the U.S. and to identify policies that could prevent these tragedies. While mass shootings continue to devastate the nation in 2018, this issue gives a comprehensive look into the mass shootings tracked by Everytown from 2009 until the end of 2017.

Everytown’s analysis revealed the following:

  • From 2009 to 2017, there were at least 173 mass shootings in the U.S.
  • 2017 was the deadliest year on record for mass shootings. There were four times as many people shot in mass shootings in 2017 than the average of the eight years prior.
  • In at least one-third of mass shootings, the shooter was legally prohibited from possessing firearms at the time of the shooting.
  • In half of mass shootings, the shooter exhibited warning signs indicating that they posed a danger to themselves or others before the shooting.
  • The majority of mass shootings were related to domestic or family violence. These incidents were responsible for 86 percent of mass shooting child fatalities.
  • Mass shootings that involved the use of high-capacity magazines resulted in more than twice as many fatalities and 14 times as many injuries on average compared to those that did not.

The findings in this report reaffirm the value of gun violence prevention policies that address the circumstances that frequently underly mass shootings. These policies include:

1. Background checks on all firearm sales to prevent prohibited people from buying guns

2. Red Flag Laws that allow family members and law enforcement to seek the temporary removal of guns from individuals who have exhibited recent dangerous behavior

3. Strong domestic violence laws that keep guns away from abusers

4. Restrictions on the purchase, possession, and manufacture of high-capacity magazines that limit the rounds of ammunition shooters can fire without reloading


Everytown defines a mass shooting as an incident in which four or more people, not including the shooter, are killed with a firearm.

To identify the 173 mass shootings included in this analysis, Everytown compiled data from media reports, police and court records, and publicly available databases for every identified mass shooting between 2009 and 2017.Because of the reliance on media reports for much of these data, disparities in local media coverage may lead to an undercount of incidents. Everytown’s researchers requested official police and court records for all 173 mass shootings, and acquired records that contained data of interest to this analysis for 77 incidents.

Chicago, IL

The objective of Everytown’s mass shooting database is to track, investigate, and analyze the nature of multi-victim shootings in the U.S. To that end, this annual report includes mass shooting incidents that occur in both public and private spaces, have any number of shooters, and result from a myriad of motives (including but not limited to random acts of violence, domestic or family violence, incidents connected to terrorist activity, and group violence). The casualty and injury figures discussed in this report include only victims of gunshot wounds and do not include the perpetrator.


Nine-year overview

By tracking mass shootings across America, Everytown identified 173 mass shooting incidents that occurred between 2009 and 2017. The vast majority of incidents—59 percent—took place entirely in private homes (102 incidents).

In nine years, mass shootings resulted in at least 1,793 people shot, including 1,001 people shot and killed and 792 shot and injured. One in five victims were children under the age of 18. In addition to the victims, at least 70 shooters also died by suicide after perpetrating a mass shooting, and another 17 were killed by responding law enforcement.

Mass shooting incidents by year 2009 - 2017

Data Spotlight: 2017

2017 was the deadliest year on record for mass shootings in the U.S.

Las Vegas, NV

Mass shootings made national headlines several times throughout 2017. Only six days into the year, a shooting at Florida’s Fort Lauderdale–Hollywood International Airport left five dead and six injured. Later in the year, the Las Vegas, NV shooting at the Route 91 Harvest Festival shocked the nation with 58 people killed and 413 more left with gunshot wounds – the highest death toll from a mass shooting the country has seen in modern times. Only one month later, 25 people were shot and killed and 20 were shot and injured in a shooting at a church service in Sutherland Springs, TX—nine of which belonged to three generations of the same family—adding to an already staggering toll. But most mass shootings do not make national headlines.

Deaths and injuries in mass shootings by year

Through the end of 2017, Everytown identified 18 mass shooting incidents. These mass shootings resulted in 611 people shot, including 159 shot and killed and 452 shot and injured. The mass shooting death toll of 2017 surpassed every other year in this analysis, making 2017 the deadliest year on record for mass shootings in the U.S. In fact, in 2017, mass shootings resulted in four times as many people shot than the average of the eight years prior.Mass shootings in 2017 resulted in 159 people shot and killed and 452 people shot and injured, compared to 105 shot and killed and 43 shot and injured per year on average from 2009 to 2016. While this report includes only incidents in which multiple victims were shot and killed, mass shooting databases that include incidents in which multiple victims were shot but survived put the number of mass shooting incidents in the hundreds each year.

Prohibited Purchasers

1. Many shooters were prohibited from possessing firearms

Federal law has long recognized that it is dangerous for felons, domestic abusers, or those with serious mental illnesses to have guns. The harm posed when guns get into the wrong hands is particularly evident in mass shootings. In at least one-third of mass shootings (59 incidents), the shooter was legally prohibited from possessing firearms at the time of the shooting.Federal and state laws prohibit people from possessing firearms for a number of reasons, including felony convictions, domestic violence misdemeanor convictions, some domestic violence restraining orders, and certain serious mental illnesses, among other reasons. Everytown reviewed media reports and available court documents to determine if shooters were likely prohibited from possessing firearms under federal or state law.

In at least one-third of mass shootings, the shooter was legally prohibited from possessing firearms at the time of the shooting

Background checks have blocked over 3.5 million sales to people with felony convictions, domestic abusers, fugitives, and other people prohibited by law from having guns.

Background checks are the foundation of a comprehensive approach to gun violence prevention. The federal background check system is designed primarily to enforce legal prohibitions and keep guns out of the hands of people who should not have them. Under federal law, licensed dealers are required to run a background check at the point of sale to identify prohibited buyers and stop the sale. This process is effective: since the system was established in 1994, background checks have blocked over 3.5 million sales to people with felony convictions, domestic abusers, fugitives, and other people prohibited by law from having guns.Karberg JC, Frandsen RJ, Durso JM, Buskirk TD, Lee AD. Background Checks for Firearm Transfers, 2015 - Statistical Tables. Bureau of Justice Statistics. November 2017.

But federal law does not cover sales by unlicensed sellers, enabling criminals and other prohibited people to buy guns from unlicensed sellers with no background check and no questions asked—including from people they meet through online marketplaces. This loophole for unlicensed sales makes it easy for millions of guns to change hands each year without a background check.Miller M, Hepburn L, Azrael D. Firearm acquisition without background checks: results of a national survey. Annals of Internal Medicine. 2017 Feb 21;166(4):233-239. In fact, one study estimated that 22 percent of gun owners acquired their most recent firearm without a background check.Id. At the time of publication, 20 states and Washington, D.C. had acted to close this dangerous loophole by requiring background checks on all handgun sales.California (Cal. Penal Code §§ 27540, 27545, 28220, 28050); Colorado (Colo. Rev. Stat. §18-12-112); Connecticut (Conn. Gen. Stat. §§ 29-33(c), 29-37a(d)); Delaware (Del. Code tit. 11, § 1448B(a)); Hawaii (Haw. Rev. Stat. §134-2); Iowa (Iowa Code § 724.15); Illinois (430 Ill. Comp. Stat. §§ 65/2, 65/3); Maryland (Md. Pub. Safety Code § 5-124(a)); Massachusetts (Mass. Gen. Laws ch. 140, § 128A); Michigan (Mich. Comp. Laws §§ 28.422, 28.426); Nebraska (Neb. Rev. Stat. §§ 69-2403, 69-2404, 69-2411); Nevada (Nev. Rev. Stat. § 202.254); New Jersey (N.J. Stat. § 2C:58-3(a), (b)); New York (N.Y. Penal Law § 400.00(4); N.Y. Gen. Bus. Law § 898(1)); North Carolina (N.C. Gen. Stat. § 14-402(a)); Oregon (Or. Rev. Stat. § 166.435); Pennsylvania (18 Pa. Cons. Stat. § 6111(c)); Rhode Island (R.I. Gen. Laws §§ 11-47-35(a)(2), 11-47-35.2(b)); Vermont (Vt. Stat. tit. 13, § 4019); Washington (Wash. Rev. Code § 9.41.113).

In the absence of laws that close the unlicensed sale loophole, criminals and other prohibited people can easily avoid background checks simply by buying guns from unlicensed sellers—including strangers they meet online.

This is exactly how a convicted felon was able to buy the firearm he used to shoot and kill four people on December 1, 2014 in Morgantown, WV. Years before the shooting, he had been convicted of felony kidnapping and wanton endangerment for abducting a former girlfriend and holding her hostage at gunpoint. As a result of the conviction, he was prohibited from buying and possessing firearms.Mayo B. Police: West Virginia shooter held personal, professional grudges. Pittsburgh Action News. December 2, 2014. If the shooter had tried to purchase a firearm at a licensed gun dealer, a background check would have stopped the sale. But neither Federal nor West Virginia law requires background checks for gun sales involving sellers who are not licensed gun dealers. So the shooter found a 9mm handgun listed for sale on Facebook and purchased it from a fellow West Virginian who had posted the ad.UPDATE: No charges for seller who sold gun to WV killer. WTAP. December 8, 2014. He used the gun to shoot and kill four people: a business rival, an ex-girlfriend and her boyfriend, and his cousin. Finally, the shooter used the same gun to shoot and kill himself.

A background check is only as good as the records in the FBI’s National Instant Criminal Background Check System (“NICS”)—the system that enables a quick determination on whether a prospective gun buyer is eligible to buy firearms—and the submission of those records largely falls on state courts and law enforcement agencies. While closing loopholes in the current federal system can further prevent firearms from making their way into the hands of prohibited purchasers, every missing record presents a public safety danger. In the past 10 years, 35 states have improved records reporting by passing new reporting laws and 16 states have improved existing laws.Alabama (Code of Ala. §§ 22-52-10.8, 22-52-10.9); Alaska (Alaska Stat. §§ 44.41.045, 47.30.907); Arizona (A.R.S. §§ 13-609, 14-5304, 36-540); California (Cal Pen Code § 28220; Cal Wel & Inst Code § 8100, et seq.); Colorado (CRS 13-5-142, 13-9-123, 18-4-412); Delaware (16 Del. C. § 5161(b)(13)-(14); 11 Del. C. 1448A(m); 29 Del. C. 9017(c); 11 Del. C. 8509); Florida (Fla. Stat. § 790.065); Georgia (O.C.G.A. §§ 16-11-172, 35-3-34(e); Ga. Comp. R. & Regs. r. 140-2-.17); Hawaii (HRS 334-60.5(j); HRS 560:5-311(d)); Idaho (Idaho Code §§ 67-3003; 66-356); Illinois (430 ILCS 65/3.1(e)(2); 430 ILCS 65/8.1(b); 405 ILCS 5/6-103.1; 740 ILCS 110/12 (b)); Indiana (Ind. Code Ann. §§ 11-10-4-3(e), 12-26-6-8(g); 12-26-7-5(c), 33-24-6-3(a)(8), 35-36-2-4(e), 35-36-2-5(f), 35-36-3-1(c), 11-10-4-3(e)); Iowa (Iowa Code 724.31); Kansas (K.S.A. §§ 75-7c25(1), 59-2966, 59-29b66); Kentucky (KRS 237.108(1)); Louisiana (La. R.S. § 13:753); Maine (34-B M.R.S. § 3864(12); 25 M.R.S. § 1541(3)(C)); Maryland (Md. PUBLIC SAFETY Code Ann. § 5-133.2); Massachusetts (ALM GL ch 6, section 167A; ALM GL ch 123, section 35; ALM GL ch 123, § 36C; ALM GL ch 215, § 56C); Minnesota (Minn. Stat. § 253B.24); Mississippi (Miss. Code Ann. §§ 45-9-103, 9-1-49); Missouri (§§ 630.140 (5); 552.030(7); 43.503(6)-(7) R.S.Mo.); Nebraska (R.R.S. Neb. § 69-2409.01); Nevada (Nev. Rev. Stat. Ann. §§ 174.035(9); 175.533(3); 175.539(4); 178.425(6); 433A.310; 159.0593(1); 179A.163(1)); New Jersey (N.J. Stat. §§ 30:4-80.10, 30:4-24.3a); New Mexico (NM Stat Ann. 34-9-19); New York (NY CLS Men Hyg §§ 7.09; 13.09; 31.11; 33.13.); North Carolina (N.C. Gen. Stat. § 14-409.43); North Dakota (N.D. Cent. Code 62.1-02-01.2); Oklahoma (21 Okl. St. § 1290.27(A)); Oregon (ORS § 181A.290); Pennsylvania (18 Pa.C.S. 6111.1(f)(3)); Rhode Island (R.I. Gen. Laws § 40.1-5-8); South Carolina (S.C. Code Ann. § 23-31-1020); South Dakota (S.D. Codified Laws §§ 23-7-47-48, 27A-10-24); Tennessee (Tenn. Code Ann. §§ 16-10-213; 16-11-206; 16-16-120; 33-3-115; 33-3-117); Texas (Tex. Gov’t Code §§ 411.052; 411.0521); Vermont (13 VSA 4824, 18 VSA 7617a); Virginia (Va. Code Ann. §§ 37.2-819, 19.2-390, 19.2-169.2); Washington (Rev. Code Wash. (ARCW) § 9.41.047); West Virginia (W. Va. Code § 61-7A et seq.); Wisconsin (Wis. Stat. § 175.35(2g)(d)(1); Wis. Stat. §§ 51.20(13)(cv)(4), 51.45(13)(i)(1), 54.10(3)(f); 55.12(10)). An Everytown analysis found that states with mental health reporting laws submitted more than twice as many records per capita as states without these laws.Everytown for Gun Safety. Fatal gaps: How the Virginia Tech shooting prompted changes in state mental health records reporting. July 2018. Despite progress, there are likely hundreds of thousands of prohibiting records that remain missing from NICS.Id. Without a background check system that is complete with all necessary records, prohibited people—including those who are at very high risk of violence—will continue to be able to purchase firearms without restriction.

Warning Signs

2. There were often warning signs before mass shootings

In the aftermath of a mass shooting, survivors, the community, and policymakers try to understand whether the shooting could have been prevented. In pursuit of this goal, experts who study mass shootings and other acts of mass violence have identified certain dangerous behaviors that can serve as warning signs that an individual is a risk to themselves or others.Consortium for Risk-Based Firearm Policy. Guns, public health, and mental illness: An evidence based approach for state policy. In this analysis, these “red flags” include, but are not limited to recent acts, attempted acts, or threats of violence towards oneself or others; convictions for certain firearms offenses; a violation of a protective order; or evidence of ongoing substance abuse.For this analysis, dangerous behaviors that would qualify as a “red flag” include any of the following, if observed within three years of the shooting: a recent threat of violence, act of violence or attempted act of violence towards self or others; a conviction for certain firearms offenses (including unlawful and reckless use, display or brandishing); a violation of a protective order; evidence of ongoing abuse of controlled substances or alcohol.

In half of mass shootings the shooter exhibited at least one red flag prior to the shooting.Everytown was able to gather red flag data on 152 of 173 mass shootings. Incidents in which warning sign data are unknown have been excluded from this calculation.


In 51% of mass shootings, the shooter exhibited dangerous warning signs before the shooting.

The case of the shooter at Pulse nightclub in Orlando, FL serves as a clear example of the lives that could be saved if family members and law enforcement recognize and act on red flags prior to such tragedies. On July 12, 2016, the shooter fatally shot 49 people and injured 53 more at Pulse, an LGBTQ nightclub in Orlando. Before the attack, warning signs pointed to his potentially dangerous behavior. His ex-wife had alleged that he was physically violent towards her: “He would just come home and start beating me up because the laundry wasn’t finished or something like that.”Goldman A, Warrick J, Bearak M. ‘He was not a stable person’: Orlando shooter showed signs of emotional trouble. The Washington Post. June 12, 2016. A recent colleague of the shooter said, “He was an angry person, violent in nature…I saw it coming…He said he was going to kill a whole bunch of people.”Perez E, Prokupecz S, Choichet CE, Hume T. Omar Mateen: Angry, violent ‘bigot’ who pledged allegiance to ISIS. CNN. June 14, 2016.

Pulse Night Club, Orlando FL

The fact that so many mass shooters displayed warning signs prior to their acts of violence highlights the opportunities to intervene and prevent these tragedies. Red Flag Laws are one such opportunity. They empower law enforcement or family members to petition a court for an order to temporarily restrict a person’s access to guns if the court finds that they pose a significant risk of using them to harm themselves or others. A person subject to a Red Flag Law, sometimes called an extreme risk protection order, or “ERPO,” is prohibited from possessing or purchasing firearms and is required to relinquish their guns while the order is in effect. At the time of publication, 13 states had Red Flag Laws on the books,California (Cal. Penal Code § 18100, et. seq.); Connecticut (Conn. Gen. Stat. § 29-38c); Delaware (10 Del. Code § 7701, et seq.); Florida (Fla. Stat. § 790.401); Illinois (430 Ill. Comp. Stat. § 67/1, et seq.)); Indiana (Ind. Code § 35-47-14-1, et seq.); Maryland (Md. Pub. Safety Code § 5-601, et seq.); Massachusetts (Mass. Gen. Laws ch. 140, §§ 121, 129B(C), 131(C), 131R-Z); New Jersey (N.J. Stat. § 2C:58-23); Oregon (Or. Rev. Stat. § 166.525, et seq.); Rhode Island (RI Gen. Laws § 8-8.3-1, et seq.); Vermont (Vt. Stat. tit. 13, § 4051, et seq.); Washington (Wash. Rev. Code § 7.94.010, et seq.). including eight that passed them in 2018 alone.DE, FL, IL, MD, MA, NJ, RI, VT However, despite research showing the impact of these laws in reducing gun deaths,Everytown for Gun Safety. Red Flag Laws: Helping prevent mass shootings. July 16, 2018.,Everytown for Gun Safety. Red Flag Laws and firearm suicide prevention. October 30, 2018. ERPOs remain largely underutilized.Gerber M. A landmark 2016 law praised as an 'unbelievably powerful tool' against gun violence remains scarcely used. Los Angeles Times. September 19, 2018.,Friedman GR. Shots Not Fired: A new Oregon law takes guns from people who may do harm. The Oregonian. June 17, 2018. Because family and household members are often the first to see warning signs, the effectiveness of Red Flag Laws depends on public awareness and thorough implementation of the law.

Domestic and Family Violence-Related Incidents

3. Domestic and family violence is a driving factor in mass shootings


In at least 54% of mass shootings, the perpetrator shot an intimate partner or family member.

The majority of mass shootings in the U.S. are related to domestic or family violence. In at least 54 percent of mass shootings (94 incidents), the perpetrator also shot a current or former intimate partner or family member. Between 2009 and 2017, at least 491 people were shot and killed as a result of mass shootings related to domestic or family violence.

When American children die by gun homicide, they often die in incidents connected to domestic or family violence.Fowler KA, Dahlberg LL, Haileyesus T, Gutierrez C, Bacon S. Childhood firearm injuries in the United States. Pediatrics. 2017;140(1):e20163486. Mass shootings are no exception—86 percent of the 224 children killed in mass shootings in the past nine years have died in an incident connected to domestic or family violence.Between 2009 and 2017, at least 224 children under the age of 18 have been killed in mass shootings. At least 193 of those children have been killed in mass shooting incidents related to domestic or family violence.

Among the victims of domestic violence mass shootings are eight members of Sheena Godbolt’s family and community. Sheena lived in Lincoln County, MS with her abusive husband. Over the years, Sheena’s family had pressed charges against her husband several times. In 2015, he made threats to kill one of Sheena’s aunts. Over the next year, the violence got worse, and after he punched and strangled her, Sheena filed a temporary protective order. He was also charged with domestic violence and aggravated assault, but the charges were dropped. Even if he had been convicted of domestic violence, Mississippi state law does not prohibit domestic abusers from having firearms.Mitchell J. Two-thirds of Mississippi's mass shootings linked to domestic violence. The Clarion-Ledger. June 2, 2017.

Then on Memorial Day weekend of 2017, Sheena’s husband shot and killed her mother, her older sister, her aunt, her cousin and her cousin’s husband, her pastor’s grandson, another young boy, and a responding officer.Jeltsen M. Portrait of an American Mass Shooting. Huffington Post. October 7, 2017. “As we were jumping the fence and running through the woods, I was hearing gunshots, gunshots, gunshots,” Sheena recalled. “That was my last time seeing my family.”Id.

86% of children killed in mass shootings have died in domestic or family violence-related incidents

Sheena’s story is not unique. The connection between mass shootings and domestic violence may be explained, in part, by the role guns play in domestic violence generally. In fact, a majority of women killed by an intimate partner homicide experienced prior physical abuse and were often threatened with a weapon in the relationship.Campbell JC, Webster D, Koziol-McLain J, et al. Risk factors for femicide in abusive relationships: results from a multisite case control study. American Journal of Public Health. 2003;93(7):1089-1097.,Nicolaidis C, Curry MA, Ulrich Y, et al. Could we have known? A qualitative analysis of data from women who survived an attempted homicide by an intimate partner. Journal of General Internal Medicine. 2003;18(10):788-794. Approximately 4.5 million American women alive today report that they have been threatened with a gun by an intimate partner.Sorensen S, Schut R. Nonfatal gun use in intimate partner violence: A systematic review of the literature. Trauma, Violence, & Abuse. 2018 Oct;19(4):431-442. And the presence of a gun often turns domestic abuse fatal—access to a gun in a domestic violence situation makes it five times more likely that a woman will be killed.Campbell JC, Webster D, Koziol-McLain J, et al. Risk factors for femicide in abusive relationships: results from a multisite case control study. American Journal of Public Health. 2003;93(7):1089-1097.

Because of the risk that firearms pose when they intersect with domestic violence, a series of federal and state laws are in place to help keep guns out of the hands of domestic abusers. The strongest state laws prohibit domestic abusers and stalkers from buying or possessing guns, require background checks for all gun sales, and create processes to ensure that abusers and stalkers relinquish guns already in their possession. However, only 16 states and Washington, D.C. require abusers subject to final domestic violence restraining orders to turn in their guns.California (Cal. Penal Code §§ 29805, 29810); Colorado (Colo. Rev. Stat. § 18-6-801(8)(a)(I)(B)); Connecticut (Conn. Gen. Stat. § 29-36K(a)); Hawaii (Haw. Rev. Stat. § 134-7(g), 134-7.3(b)); Illinois (730 Ill. Comp. Stat. § 5/5-6-3(a)(9)); Iowa (Iowa Code § 724.26(4)) ; Louisiana (La. Code Crim. Proc. art. 1002(A)(2)(a)); Maryland (Md. Crim. Proc. Code § 6-234(D)); Massachusetts (Mass. Gen. Laws ch 140, §§ 129B(4), 129D, 131(f)); Minnesota (Minn. Stat. §§ 609.2242, subd. 3(f), (g), (h), 609.749, subd. 8(d)); Nevada (Nev. Rev. Stat. §§ 200.485(9), 202.360; 2017 NV S 124, § 5); New Jersey (N.J. Stat. § 2C:25-27(c)(1)); New York (N.Y. Penal Law §§ 265.00(17), 400.00(11)); Pennsylvania (18 Pa. Cons. Stat. § 6105(a)(2)); Rhode Island (R.I. Gen. Laws § 11-47-5.4); Tennessee (Tenn. Code § 39-13-111(c)(6)); Washington, D.C. (D.C. Code §§ 7-2502.09(a)(1), §7-2502.03(a)(4)(D), 7-2502.10).

Evidence shows that when these laws are on the books and enforced properly, they work to reduce domestic violence-related homicides. State laws that prohibit individuals subject to domestic violence-related restraining orders from possessing firearms and also require them to relinquish their firearms are associated with a 10 to 12 percent lower intimate partner homicide rate, and a 14 to 16 percent lower intimate partner firearm homicide rate.Zeoli AM, McCourt A, Buggs S, Frattaroli S, Lilley D, Webster DW. Analysis of the strength of legal firearms restrictions for perpetrators of domestic violence and their associations with intimate partner homicide. American Journal of Epidemiology. 2018 Nov 1;187(11):2365-2371.,Díez C, Kurland RP, Rothman EF, et al. State intimate partner violence-related firearm laws and intimate partner homicide rates in the United States, 1991-2015. Annals of Internal Medicine. 2017 Oct 17;167(8):536-543. States with laws that prohibit firearm possession by those convicted of any violent misdemeanor—not exclusive to domestic violence—were associated with a 23 percent reduction in the intimate partner homicide rate and a 21 percent reduction in the intimate partner firearm homicide rate.Zeoli AM, McCourt A, Buggs S, Frattaroli S, Lilley D, Webster DW. Analysis of the strength of legal firearms restrictions for perpetrators of domestic violence and their associations with intimate partner homicide. American Journal of Epidemiology. 2018 Nov 1;187(11):2365-2371. Because the majority of mass shootings involve domestic or family violence, laws that reduce domestic violence gun homicides may also be effective at preventing mass shootings.

High-Capacity Magazines

4. Mass shootings involving high-capacity magazines result in more deaths and injuries

It is no coincidence that the deadliest mass shootings in this analysis all involved the use of high-capacity magazines (Las Vegas, Orlando, Newtown, Sutherland Springs, San Bernardino). High-capacity magazines (HCMs)—defined as capable of holding more than 10 rounds of ammunition—allow a shooter to fire more rounds without pausing to reload. The more rounds a shooter can fire consecutively, the more gunshot wounds they can inflict during an attack.Koper C, Woods D, Roth J. Report to the National Institute of Justice, United States Department of Justice. An updated assessment of the Federal Assault Weapons Ban: impacts on gun markets and gun violence, 1994 - 2003. Published June 2004.


58% of mass shootings involved high-capacity magazines.

Of the 60 incidents in which information on magazine capacity was available, over half—58 percent—involved firearms with HCMs.Everytown acquired information on the type of magazine used in 60 incidents. Incidents in which magazine capacity was unknown have been excluded.

Of mass shootings with known capacity data (60), those that involved the use of HCMs resulted in twice as many fatalities with 14 times as many injuries per incident on average compared to those without.The 35 incidents with confirmed use of high-capacity magazines resulted in 10.1 deaths and 19 injuries per incident on average, compared to the 4.6 deaths and 1.3 injuries on average that resulted from the 25 incidents confirmed to have not included the use of high-capacity magazines. Even after removing the October 2017 shooting in Las Vegas, HCMs still resulted in nearly twice as many fatalities and six times as many injuries.After excluding Las Vegas due to its anomalously high toll, the 34 incidents with confirmed use of high-capacity magazines resulted in 8.7 deaths and 7.4 injuries per incident on average.

Mass shootings involving high-capacity magazines (HCMs)

The 2009 Fort Hood shooter—who shot and killed 13 people and injured 32 more—specifically sought out HCMs in preparation for his attack. A witness to the shooter’s purchase at a Killeen, TX gun dealer reported, “He gave me two specifications. He said he wanted the most technologically advanced weapon on the market, and the one with the highest magazine capacity.”Huddleston, S. Hasan sought gun with ‘high capacity magazine.’ My San Antonio. October, 21, 2010.

Restricting the manufacture, transfer, and possession of high-capacity magazines can reduce the number of mass shootings. A study of mass shootings found that states with restrictions on magazine size experience mass shootings at half the rate of states without the restrictions.Petulla S. Here is 1 correlation between state gun laws and mass shootings. CNN. October 5, 2017. Authors of this study defined mass shootings as incidents with three or more victims. According to Dr. Michael Siegel, a researcher at Boston University, “Whether a state has a large capacity ammunition magazine ban is the single best predictor of the mass shooting rate in the state.”Id. Currently, eight states and Washington, D.C. restrict the manufacture, transfer, or possession of HCMs.California (Cal. Penal Code § 32310); Colorado (Colo. Rev. Stat. § 18-12-302(1)); Connecticut (Conn. Gen. Stat. § 53-202w(b)-(c)); Hawaii (Haw. Rev. Stat. § 134-8(b)); Maryland (Md. Crim. Law Code § 4-305(b)); Massachusetts (Mass. Gen. Laws ch. 140, § 131M.); New Jersey (N.J. Stat. § 2C:39-3(j)); New York N.Y. Penal Law §§ 265.10(1)-(3), (6); 265.36); Vermont (Vt. Stat. tit. 13, § 4021(a)); Washington, D.C. (D.C. Code § 7-2506.01(b)).


Mass shootings have a devastating impact on our communities—from the victims killed, to the surviving witnesses and community members, to the public at large. In order to prevent such tragic violence in the future, we must understand how and why these incidents unfold.

The true picture of mass shootings in the U.S. is different than headlines suggest. While there are prominent attacks in public places, the majority of these shootings occur in the home—between spouses, partners, and family members. The events documented in this report were not inevitable. Policymakers across the country should address the gaps that make it too easy for dangerous individuals to arm themselves. This includes requiring background checks on all firearm sales, temporarily removing firearms through Red Flag Laws, keeping guns out of the hands of domestic abusers, and restricting the purchase, possession and manufacture of high-capacity magazines.


Click here to download an appendix of the shootings profiled in this analysis.

Previous Editions of Mass Shootings in the United States

Mass Shootings in the United States: 2009 to 2016 (2017)