America’s Mass Shootings

Are mass shootings on the rise?

In the aftermath of the tragic mass shooting at the Emanuel African Methodist Episcopal Church in Charleston, South Carolina, President Obama addressed the U.S. public on June 18, 2015 for the seventh time on the issue of mass shootings for the seventh time during his presidency:

“I’ve had to make statements like this too many times. Once again, innocent people were killed in part because someone who wanted to inflict harm had no trouble getting their hands on a gun.”

Mass shootings have been on the rise in the U.S. According to data analysis by the Harvard School of Public Health, mass shootings have been more frequent in the past few years. In fact, a report released by the FBI in 2014 reveals that mass shootings in the U.S. have been increasing since 2000. The FBI report, which defines a “mass shooting” as any event that leads to the ?death of four or more people, states that an average of 11.4 incidents occurred annually between 2000–2013. These shootings occurred in forty out of the fifty states, as well as the District of Columbia.

The Mass Shooting Tracker (2013-present), a crowd-sourced database for mass shooting incidents in the U.S., aims to contest the FBI’s definition of “mass shootings” by defining the term as any incident that leads to the shooting of four or more people as well.

According to annual data collected from the Mass Shooting Tracker, 2013 was the deadliest year for mass shootings in terms of the number of people killed and injured. During that year, an estimated 502 people were killed and 1,266 were injured.

Total Killed and Wounded by Year

Source: Mass Shootings Tracker

Since 2013, the U.S. has witnessed several fatal mass shootings. The deadliest shooting, in terms of the number of people killed, occurred in 2013 when 34-year-old Aaron Alexis, a government contractor, killed 13 people inside the Navy Yard in Washington, D.C. The second deadliest shooting occured in 2015, when 21-year-old Dylann Roof killed nine people inside a church in Charleston, South Carolina. The third deadliest shooting, also in 2015, occurred at the Twin Peaks restaurant in Waco, Texas. The mass shooting, which left 9 people dead and 18 injured, is still under investigation and led to the detention of 239 people at the crime scene; only 62 of them were released without charge.

Deadliest Mass Shootings

Source: Mass Shootings Tracker

The top-2 deadliest shootings, in terms of the number of people injured, were carried out by unknown perpetrators. The third deadliest mass shooting occurred on April 2, 2014, when 34-year-old Ivan Lopez, an Army Specialist, killed three people and injured 16 others before killing himself. In another case, 18-year-old Randy Stewart carried out a mass shooting in a house party — killing two people and injuring 16 others.

Mass Shootings With Most Injured

Source: Mass Shootings Tracker

Between 2013–2015, hundreds of people were killed in mass shootings all over the country. The map belows shows mass shooting incidents that led to over four deaths in total. The mass shootings carried out by Aaron Alexis, Dylann Roof, and Don Charles Spirit, who killed his daughter and six children in Florida before killing himself, remain the deadliest mass shooting during that period.

Mass Shootings Mapped — Number of People Killed 2013–2015

Source: Mass Shootings Tracker

Beyond nationwide data, state statistics show that mass shootings are more prevalent in some states than in others. An analysis of each state’s recorded population and death count per capita shows that mass shootings are not restricted to a certain region in the U.S.; there are several outlier states with high fatalities from mass shootings, including California, Texas, Florida, and New York.

Source: Mass Shootings Tracker

Ultimately, the analysis of data provided by the Mass Shooting Tracker reveals an alarming yet somewhat recognized finding: the majority of mass shootings, as defined by the Mass Shooting Tracker, are carried out by unknown perpetrators. In fact, 94.6% of shootings in the database were committed by unknown shooters and only 4% of mass shootings had established or alleged shooters. Since 2013, there have only been nine cases (1.4%) where the perpetrator was known, but undisclosed.

Source: Mass Shootings Tracker

Regardless of how the term “mass shootings” is defined, the Mass Shooting Tracker and the FBI report both point to one conclusion: mass shootings are on the rise. Prior to 2013, the year the Mass Shooting Tracker database launches, the U.S. witnessed some of the deadliest mass shootings in its history, including the mass shooting at Virginia Tech, which led to the death of 32 people and the injury of 17 others, and the mass shooting at the Sandy Hook Elementary School in 2012 in which 28 people were killed. Overall, an estimated 52% of the top-25 deadliest mass shootings since 1949 occurred during the 2000s. As Mark Follman outlines in MotherJones: “It’s not a matter of if, but when and where the next mass shooting will happen.”

Explore the interactive visualizations in this piece on Silk.