The school shooting at Marjory Stoneman Douglas High School in Parkland, Fla., stoked many questions about safety, guns, and the psychology behind such attacks. Here鈥檚 what the research says about school shootings.
What counts as a school shooting?
Advocacy and research organizations use widely varying criteria about which incidents should be considered school shootings, leading to sometimes conflicting figures in news reports.
, a group that advocates for more-restrictive gun laws, includes in its count any incident in which 鈥渁 firearm discharges a live round inside a school building or on a school campus or grounds,鈥� including on the campuses of colleges and universities. That count includes suicides and incidents that did not result in injuries, like the accidental discharge of a security guard鈥檚 weapon.
Other organizations only track mass shootings, using differing criteria for what is involved in such incidents. Those lists leave out many school shootings that don鈥檛 meet the minimum threshold for injuries and deaths, but that still had significant effects on schools and communities.
Federal data on school shootings are limited. The annual Indicators of School Crime and Safety Report鈥攁ssembled by the U.S. Departments of Justice and 91制片厂视频鈥�, breaking them into categories of suicides and homicides. But that data do not specify what, if any, weapons were used in those incidents, and they don鈥檛 include a breakdown of firearm injuries in schools.
91制片厂视频 Week鈥榮 tracker includes shootings with firearms at K-12 schools, on school buses, or at school events that resulted in at least one firearm-related injury to an individual who was not the suspect. The total count of injuries for each incident may be minor or major and are not necessarily the result of gunfire.
Are school shootings becoming more common?
Heavy news coverage and social media discussions about school shootings, like the one in Parkland, have stoked fears that the number of school shootings have increased dramatically in recent years. Experts who study mass shootings, including those in schools, say that they are not happening more frequently, but many of them are more deadly than past attacks.
Three of the deadliest mass shootings in U.S. history have happened in the last year, including Parkland, which ranks eighth. Federal data appear to contradict popular notions that schools have grown significantly less safe in recent years.
The numbers of school-associated violent deaths in the last 20 years. Other forms of student victimization are on a downward trend, and fewer students report at school than in previous years, the most recent federal data show.
Do school shooters fit a specific profile?
There are widely held beliefs about the 鈥減rofile鈥� of a student shooter, but school safety experts say acts of school violence have been carried out by attackers of all races, ages, disciplinary histories, and family backgrounds.
School safety experts say it鈥檚 important for schools to take all threats and concerns seriously, regardless of the profile of the student involved.
A 2002 report by the U.S. Secret Service National Threat Assessment Center, prepared after the agency analyzed 37 school shootings, concluded that 鈥渢here is no accurate or useful 鈥榩rofile鈥� of students who engaged in targeted school violence.鈥�
In the incidents analyzed, attackers fell all along the social spectrum, from popular students to 鈥渓oners,鈥� the Secret Service report said. While the agency didn鈥檛 find common demographic threads, it did note some psychological trends among attackers: Many 鈥渇elt bullied, persecuted, or injured by others prior to the attack,鈥� many had a history of suicide attempts or feelings of depression or desperation, and most had no history of criminal behavior.
School shooting suspects are , and researchers have various theories about why.
鈥淭he fact that school shooters are typically male is part of the overall phenomenon of violence being a predominantly male phenomenon,鈥� said Peter Langman, a psychologist who studies school shootings and has authored several books about them.
In the case of 鈥渞ampage shootings,鈥� perpetrators often have a sense of 鈥�,鈥� which Langman defines as a sense of failure or inadequacy in parts of their life that they have linked to male identity, like sexuality or physical strength, he said.
What can be done to prevent school shootings?
As the public searches for answers after a school shooting, family members and classmates often suggest it was an , saying things like 鈥淗e just snapped.鈥�
But psychologists and school safety experts say that鈥檚 rarely the case. One of the most important ways to keep schools safe is to create a consistent, reliable system for reporting and responding to concerns about students鈥� intentions, they say.
鈥淚 think this idea of 鈥榡ust snapped鈥� really undermines the importance of ongoing risk management and assessment,鈥� Anders Goranson, a psychologist and threat-assessment specialist, said in a lecture at the annual meeting of the American Psychological Association in 2014. People need to feel empowered to share information or conversations that 鈥渕ade the hair stand up on the back of their neck,鈥� he said.
The U.S. Secret Service report concluded that attackers in 31 of 37 analyzed shooting incidents had told at least one person about their plans beforehand. In 22 cases, two or more people knew about the planned attack in advance, the study concluded. In nearly all cases, those peers were classmates, siblings, and friends of the attackers, it said.
That idea of 鈥渓eakage鈥� has motivated many states and school systems that allow youth to report suspicious behavior by their peers. The operators of a tipline in Colorado, which was started after the school shootings at Columbine High School in 1999, believe that system has helped dismantle the plans of multiple would-be school shooters.
Sandy Hook Promise, an organization formed by parents of children who died in the 2012 Newtown, Conn., school shootings, also works to train schools in threat assessment. In special sessions, teachers learn to identify and address concerns. The organization also works with students to encourage speaking up when peers contemplate harming themselves or others in a campaign called 鈥淪ay Something.鈥�
Are guns the only threat to school safety?
Guns are not the only threat to school safety, though most public policy discussions are centered on the risk of school shootings.
In 2014, a 16-year-old boy when he went on a stabbing spree with two large kitchen knives in a crowded hallway of his Pennsylvania high school.
And the happened in 1927, when a man blew up a school in Bath Township, Mich., with hundreds of pounds of dynamite. Forty-five people died, including 38 children and the attacker himself.
Video: How Schools Should Respond to a Student鈥檚 Threats
School shootings have led teachers and administrators to rethink their actions when a student makes a threat. Dewey Cornell, a professor of education at the University of Virginia, has been studying school violence for decades and has developed guidelines for schools to follow:
