Schools have become savvier about how to prevent attacks in the decade since the mass killing at Columbine High. They have trained staff to spot the signs of a student carrying a weapon and created teams of police and school officials to respond to potential threats.
"It really did create a massive movement in the United States for improved school safety," says Michael Dorn, executive director of Safe Havens International, a nonprofit school safety organization in Macon, Ga. From talks with school leaders around the country, Mr. Dorn estimates that hundreds of planned attacks have been averted: "To me, that's an incredible success."
The concern today is that tight budgets and short memories could mean waning vigilance. Moreover, many schools might be relying too heavily on technology and physical security, rather than tackling the more important challenge of creating a supportive culture on campus.
Ninety percent of 435 schools and universities said they are safer now than when the Columbine shootings took place 10 years ago Monday, according to a recent survey by Campus Safety Magazine. After Columbine, for example, 49 percent of K-12 schools created or expanded "multidisciplinary threat assessment" teams – administrators, teachers, police, and counselors who identify and respond to situations they see as potential threats.
The importance of a school's culture and emotional climate emerged in a series of reports after Columbine, conducted jointly by the US Department of Education and the Secret Service. Examining 37 incidents of school violence between 1974 and 2000, researchers found that 93 percent of the perpetrators had exhibited concerning behaviors in advance of the attacks. In 81 percent of the cases, at least one bystander had some prior knowledge of the threat.
"Kids don't just snap," says William Pollack, a scientific investigator for the studies and director of the Center for Men and Young Men at Harvard's McLean Hospital. To a large extent, he says, the school attackers had struggled with depression, had been in trouble with school officials, or had spoken openly about wanting to commit a violent act.
"Positive connections of an emotionally meaningful sort [in school] are one of the best ways to assure that school violence will not occur, and also one of the best ways to know that if someone is on the edge of engaging in something like a shooting ... someone will come forward and let authorities know," Dr. Pollack says.
Tips from students have foiled many of the most ambitious plots since Columbine. In May 2001, in Elmira, N.Y., a friend of high-school senior Jeremy Getman passed along to authorities a suspicious note from Mr. Getman, and police found Getman in the cafeteria with a pistol, 18 bombs, and a sawed-off shotgun, according to media reports. Three years later in Clinton Township, Mich., Andrew Osantowski said during an Internet chat that he was planning to attack his school, and that tip led police to Mr. Osantowski's house, where they found stolen weapons, an AK-47, and Nazi literature, reports say.
In one of the joint reports focused on bystanders, students reported that they held back information if they didn't trust the adults or if they had seen adults' actions not match up with their words about the importance of a caring environment.
Parents and other adults outside school play an important role, too. One student who helped avert a planned school shooting noted that his mother encouraged him to share his concerns with officials. He was also motivated by Columbine. The student said in the report: "If not for Columbine, I might have thought twice about coming forward, but I couldn't be one of those who sat by."