A deadly shooting at a Colorado school last week was the 4th such school shooting in the Denver area and at least the 111th in the country since 1970, according to a New York Times analysis.
A shooting at a school in Highlands Ranch, Colorado, last Wednesday in which one student was killed and eight others were wounded swiftly drew comparisons to the 1999 attack on nearby Columbine High School and the dozens of shootings like it in the years since.
The attack was the fourth such school shooting in the Denver area and at least the 111th in the country since 1970, according to a New York Times analysis — the latest in a decades long series of violent episodes that have shocked the nation and traumatised generations of students.
The Times examined hundreds of episodes in a database of shootings at elementary, middle and high schools to identify those cases where, like at Highlands Ranch and Columbine, the assailants planned their attacks and fired indiscriminately.
A total of 202 people were killed in these attacks and 454 were wounded, including the shooters. In 16 cases, shots were fired but no one was injured.
Last year was particularly violent: 29 people were killed and 48 were injured in three shootings in Parkland, Florida; Sante Fe, Texas; and Benton, Kentucky.
Shootings of this type are rare relative to the larger universe of gun violence at schools, but they are common enough that lockdown drills and "run, hide, fight" exercises are part of the school experience all over the country. Before Highlands Ranch there was Marjory Stoneman Douglas. Before Marjory Stoneman Douglas there was Sandy Hook. Before Sandy Hook, Columbine; and before Columbine, Cleveland Elementary in Stockton, California.
The school shootings database, compiled by the Naval Postgraduate School's Center for Homeland Defence and Security, is the most comprehensive and detailed of its kind. Researchers aimed to document all instances of gunfire at K-12 schools since 1970 and recorded more than 1,300 cases. The database does not include shootings on college campuses.
The Times' analysis identified the 111 cases that met the FBI's definition for an active-shooter scenario, in which an assailant is actively engaged in killing or attempting to kill people, on school property or inside school buildings.It excluded episodes that fit more typical patterns of gun violence such as targeted attacks, gang shootings and suicides.
These events have stunned much of the country and, in the case of the Parkland shooting, inspired a national student-led movement to tighten the nation's gun laws. But they account for only a small fraction of the episodes of gun violence that children experience in U.S. schools.
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Other cases might include a student showing off a gun to friends in the hallway, the accidental discharge of a school resource officer's gun, or a gang-related drive-by shooting at a school bus stop.
"There are shootings that occur in very wealthy counties and very poor counties, ones that happen in very diverse areas and very homogeneous areas," said David Riedman, co-creator of the database.
Active shooters might attack anywhere, but a demographic analysis shows they tend to have traits in common. The majority of shooters were young white men or boys, many of them current or former students of the schools where they opened fire.
Some shooters followed a now-familiar blueprint. Peter Langman, a psychologist who studies school shooters, said younger assailants are especially likely to find inspiration in earlier events. "More than anyone else, people cite the Columbine killers," Langman said.
That episode intensified a debate over gun violence that continues to divide the nation and drove districts to allocate hundreds of millions of dollars to "harden" schools against threats.
The Highlands Ranch shooting similarly renewed old questions about gun access and how best to protect students from shootings. At a vigil for the victims Wednesday, Colorado's senior senator criticized the country's gun laws.
Riedman, who spent hours poring over news reports and public records on hundreds of shootings to build the database, said school safety measures should take into account not only the incidents like Columbine but also the many other ways guns and schools can intersect in America.
"These shootings have been carried out by all sorts of people, from students to total strangers," Reidman said. "They've happened in any part of the country, and they've happened for just about every reason, and that makes prevention very difficult. There can't be any one single or simple solution that's going to address this problem."
How many school shootings have there been in 2019?
Across the country this year, according to media reports, at least eight shootings have taken place on high school or college campuses. They have occurred inside gyms and classrooms, in parking lots and school hallways.
Altogether, four people have been killed and 17 wounded, according to law enforcement authorities and media reports, with two recent shootings — at a university in Charlotte, North Carolina, last week and at a school in Highlands Ranch, Colorado, this week — accounting for the bulk of the toll.
The New York Times defined a school shooting as one that occurred on campus and involved students, either as the accused perpetrators or the victims.
January 31, Memphis, Tennessee
A 14-year-old at Manassas High School in Memphis was shot with a pellet gun at school, according to news reports. The student's injury was not life-threatening.
February 8, Baltimore, Maryland
A man entered Frederick Douglass High School and shot and wounded a staff member, prompting students to hide in their classrooms at the sound of gunfire. Police said they believed the gunman had targeted the victim, a 56-year-old special education assistant.
February 12, Kansas City, Missouri
A teenage girl was shot and killed outside a high school in Kansas City after an argument at an evening basketball game. Police said the assailant and girl knew each other, and that it appeared the suspect had waited in the parking lot and shot the girl as she left the game.
February 26, Montgomery, Alabama
A 17-year-old student at Robert E. Lee High School was shot and wounded in an arm by another student, police said. The school was placed on lockdown and the assailant was arrested. According to media reports, it was the second time in two years that a student had taken a gun to that school and shot another student.
April 1, Prescott, Arkansas
A 14-year-old eighth-grader at Prescott High School was shot and injured by a classmate, who the authorities said took a concealed handgun to school.
April 30, Charlotte, North Carolina
Two students were killed and four were wounded after a gunman opened fire in an anthropology class at the University of North Carolina at Charlotte. One of the students who was killed, Riley Howell, was credited with charging and body slamming the gunman, stopping the massacre.
May 7, Highlands Ranch, Colorado
One student was killed and eight others were injured this week in an attack on an English class at STEM School Highlands Ranch. Two students were apprehended and charged with the shooting, which took place just miles from Columbine High School, the site of a massacre 20 years ago.
May 7, Savannah, Georgia
A Savannah State University student was shot and wounded in a residential hall on campus. Authorities said a man who was not a student was arrested in the shooting.
- Julie Bosman
Written by: Weiyi Cai, Jugal K. Patel and Julie Bosman
Photographs by: Swikar Pate and Nick Cote
© 2019 THE NEW YORK TIMES