Last year was the deadliest year on record for public mass shootings in American history. More than 100 people were killed in 30 incidents in the U.S. in 2017, according to the FBI.
In the wake of these incidents, we often hear “no one could have seen this coming,” or “this person just snapped.” But what do we know about the perpetrators of mass shootings?
The FBI recently released a report on the behavior of “active shooters,” which the Bureau defines as “an individual (or individuals) actively engaged in killing or attempting to kill people in a populated area.”
“Mass shooter,” the term most often associated with perpetrators of incidents like the Sandy Hook Elementary shooting, is not defined by the FBI.
In its report, the FBI looked at active shooters between the years 2000 and 2013, regardless of how many people (if any) were killed. The lessons apply to mass shootings and other shootings alike.
Here are five common misconceptions about the perpetrators of active shootings and what the FBI’s research revealed.
There’s “no useful profile of a mass shooter.”
Marisa Randazzo, a former chief psychologist of the U.S. Secret Service and currently managing partner at SIGMA Threat Management, discussed this with the public radio show 1A.
“There’s actually no useful profile of a mass shooter,” Randazzo said, “but there’s a lot we can look at in terms of behavior.”
For example, a recent FBI report finds that while the 63 active shooters examined in the study couldn’t be linked based on demographics alone:
62 percent of the shooters had a history of acting in an abusive, harassing, or oppressive way (e.g. excessive bullying, workplace intimidation); 16 percent had engaged in intimate partner violence, and 11 percent had engaged in stalking-related conduct.
University of Alabama Criminologist Adam Lankford says this is a common misconception about mass shooters.
According to the FBI report, only 25 percent of active shooters between 2000 and 2013 had ever been diagnosed with mental illness.
And according to a 2016 study published by the American Psychiatric Association, mass shootings by people with serious mental illness represent less than 1 percent of all yearly gun-related homicides.
It bears emphasizing: The vast majority of people with mental illness never commit violent crimes.
The FBI researched 34 active shootings between 2000 and 2013 and found that in 77 percent of the cases, the subject spent a week or longer planning the attack.
“In this context, ‘planning’ means the full range of considerations involved in carrying out a shooting attack” according to the FBI report, such as making the choice to “engage in violence” and selecting targets.
In it’s study, the FBI found that most shooters didn’t research target locations. Often, the shooters were already familiar with their intended target, such as their school or office.
Mass shootings are extremely rare. They make up less than 1 percent of all U.S. gun homicides. It is hard to predict which individuals will actually become violent.
The FBI report notes that on average, each active shooter studied displayed four to five “concerning behaviors” over time that were observable to others around the shooter.
These include recklessness, violent media usage, changes in hygiene and weight, impulsivity, firearm behavior, and physical aggression.
In its research, the FBI found that in more than half the cases where “concerning behaviors” were displayed, the first behavior was reported over two years before the shooter carried out their attack.
Sixty-three of the active shooters between 2000 and 2013 studied by the FBI displayed at least two concerning behaviors before carrying out their attack. The chart above shows the longest time between when one of these behaviors was noticed and an attack.
Marisa Randazzo says mass shooters typically go beyond just threats. She suggests observing whether someone who is making threats is also acquiring firearms or tactical gear.
The most likely people to notice these concerning behaviors? According to the FBI’s study, “classmates (for those who were students), partners (for those in relationships), family members and friends.”
According to the FBI report, 40 percent of the firearms used by shooters studied between 2000 and 2013 were purchased legally for the crime and another 35 percent were already in the shooter’s possession.
Each state regulates gun possession differently. For example, a handful of states have laws barring people convicted of criminal stalking from purchasing a firearm. Others require owners to register certain “long guns” (a firearm fired while braced against a shoulder, like a shotgun or rifle.)
Eleven states now have so-called “red flag” laws that allow law enforcement or family members to petition the court for a temporary gun violence restraining order against an individual they believe is dangerous.
Editor’s note:This piece was adapted from a post published to Medium, July 5, 2018.
Guns & America is a public media reporting project on the role of guns in American life.