How San Bernardino Compares to 30 Years of Mass Shootings

While the location changes, lots of details remain the same

Dec 03, 2015 at 6:53 PM ET

Reports of Wednesday’s shooting that claimed 14 lives and injured 21 others in San Bernardino hardly came as a shock to most in the U.S., where gun violence has become increasingly commonplace—so much to the point that President Obama has stopped using the word “shock” in statements following the events.

There have only been three years since 1982 without a mass shooting as defined by Mother Jones, which hosts a database that accounts for multiple factors surrounding each event. While Mother Jones’ database has been widely circulated, Vocativ found there’s no one answer as to what constitutes a mass shooting. In defining a mass shooting as one that results in four or more victims—up one from databases maintained by the FBI and Stanford University—Mother Jones likely holds the most conservative count. The Gun Violence Archive, for instance, puts this year’s count of mass shooting at 309.

Looking at a range of different circumstances, the San Bernardino shooting has much in common with 74 other mass shootings occurring over the past 33 years. We added to Mother Jones data with additional Vocativ reporting to include shootings conducted by more than one perpetrator not linked to terrorism. While San Bernardino was not a “lone wolf” occurrence, the details of the tragedy show that it was not otherwise atypical.

One way in which the shooting follows the pattern of other mass killing events is that at least some of the guns used to kill civilians at the disability treatment center were purchased legally.

While 16 of these shootings have occurred in California—at least twice that of any other state—its large population makes this almost predictable, while Washington state has had the largest number of these incidents per capita. More than a quarter of mass shootings have occurred at a workplace.

While mental state remains a difficult thing to assess, mental illness has been determined a factor in more than half of all mass shootings. Prior reports indicate that suspect Syed Rizwan Farook, who died in a shootout with police along with his wife Tashfeen Malik, may have been in a state of distress following an alleged argument. The vast arsenal of weapons at the couple’s disposal, however, may also hint to terrorism as a motive, though the FBI has yet to make that determination.

Perhaps the most significant difference between the San Bernardino shootings and the ones of those past is that a woman played a role in the attack. Deceased suspect Malik is among the small but rising 4 percent of female mass shooters.