Persons who committed public mass shootings in the U.S. over the last half century were commonly troubled by personal trauma before their shooting incidents, nearly always in a state of crisis at the time, and, in most cases, engaged in leaking their plans before opening fire. Most were insiders of a targeted institution, such as an employee or student. Except for young school shooters who stole the guns from family members, most used legally obtained handguns in those shootings.
Those are prominent traits of persons who have engaged in public mass shootings – that is, a shooting that kills four or more people – collected in a comprehensive new database of identified U.S. mass shootings from 1966 to 2019. The data on 172 mass public shooters cover more than 150 psychosocial history variables, such as those individuals’ mental health history, past trauma, interest in past shootings, and situational triggers.
+++++++++++++++++++++++++++++++https://www.washingtonpost.com › nation › 2022/06/02
Jun 2, 2022
Opinion: We analyzed 53 years of mass shooting data. Attacks aren’t just increasing, they’re getting deadlier
If you look at mass shootings over time, two things are alarmingly clear: The attacks are becoming far more frequent, and they are getting deadlier.
We’ve studied every public mass shooting since 1966 for a project funded by the National Institute of Justice, the research arm of the U.S. Department of Justice. Our research spans more than 50 years, yet 20% of the 164 cases in our database occurred in the last five years. More than half of the shootings have occurred since 2000 and 33% since 2010. The deadliest years yet were 2017 and 2018, and this year is shaping up to rival them, with at least 60 killed in mass shootings, 38 of them in the last five weeks.
The death count per shooting is also rising dramatically. Sixteen of the 20 most deadly mass shootings in modern history occurred in the last 20 years, eight of them in the last five years, including the 2017 Las Vegas shooting that claimed an unprecedented 58 lives.
For decades, the toll of mass shootings has risen steadily. During the 1970s, mass shootings claimed an average of 5.7 lives per year. In the 1980s, the average rose to 14. In the 1990s it reached 21; in the 2000s, 23.5. This decade has seen a far sharper rise. Today, the average is 51 deaths per year.
Mass shootings still represent just one-half of 1% of the more than 14,000 firearm-caused homicides per year in the United States, but while the number of homicides overall has declined in recent years, the number of mass shootings continues to surge.
There is no universally accepted definition of a mass shooting. But for our research at the Violence Project, we use the Congressional Research Service definition, which includes any event in which four or more victims (not including the shooter) are murdered in a public location with firearms. By that standard, the mass shooting in the Texas cities of Odessa and Midland on Saturday afternoon, in which seven people plus the shooter died, was the sixth this year.