Several factors make it difficult to get a handle on the number and frequency of mass shootings in America. Mass shootings that occurred before the advent of the Internet are difficult to track. Also, different researchers use different definitions of what constitutes a mass shooting.
I have chosen the below source because it is comprehensive and regularly updated. If you want to question the below facts, please visit the linked resource first to see how the data was gathered.
Here is a database from Mother Jones that tracks mass shootings in America. As of this post, the database has 90 mass shootings from 1982 to the present. The below numbers come from a detailed study of 62 mass shootings created by Mother Jones.
- The killers possessed a total of 143 guns.
- More than 75 percent of the 143 guns were purchased legally.
- High-capacity magazines (which allow a shooter to fire many times before reloading) were used in at least half of the mass shootings.
- Dozens of assault weapons and semi-automatic handguns with high-capacity magazines were used.
- More than half of the mass shootings took place in a school or at the killer’s workplace.
- At least 36 of the 62 killers committed suicide at or near the crime scene.
- Another seven murderers were killed by police.
- At least 38 of the killers showed signs of mental illness before their rampage.
- Forty-four of the 62 shooters were white men.
- Only one of the 62 shooters was a woman.
- The average age of the killers was 35.
- The youngest mass killer was eleven.
Mother Jones produced a guide to their study of 62 mass shootings.
Stanford University’s Mass Shootings In America is attempting to chronicle mass shootings going back to 1966.