In a training manual to be distributed to school and law-enforcement personnel, the agency that protects the president said schools should pay more attention to students' social problems, listen to their complaints, urge classmates to report problems and watch out for depressed, suicidal teen-agers if they want to head off school shootings like the one at Columbine High School in 1999.
The findings weren't surprising to several people who work in the schools.
"They're not telling us anything new," said Curt Lavarello, who heads the National Association of School Resource Officers. He and others schools have been following such suggestions for years.
"If anything, they're reaffirming the things we've said for many years now....We keep our ears to the ground, so to speak."
The Secret Service and the Education Department plan to hold training sessions based on the manual in six cities this summer.
As part of its mission to protect public officials, the Secret Service operates the National Threat Assessment Center to study and help prevent violence in public places. The center began looking into the patterns of school shootings in 1999, after two students killed themselves and 13 others in a rampage at Columbine, located in Littleton, Colo.
Investigations of school shootings since 1974 found that students who came to school with a plan to kill did not just "snap." They warned classmates, aired their grievances and left other clues.
Researchers found that in most school attacks, students knew something was about to happen. In one case, rumors of a planned shooting drew two-dozen onlookers to a school hallway before the attacker opened fire; one student had brought a video camera, but forgot to record the event.
In more than two-thirds of cases, the attackers said they felt persecuted, bullied, threatened, attacked or even injured by others just before the shootings. Many either threatened to commit suicide or actually tried it.
The Secret Service has warned strongly against profiling students, saying there is no common profile of a school shooter. Some were popular, others were not. Some made good grades; others were failing.
Some were in foster care; some came from intact families that were pillars of the community.
Rather than building a profile of an attacker with a set of personality traits, schools should focus on behavior and motives and encourage students to speak out about students who are threatening violence, researchers have said.
Based on what they've seen of report drafts, several school safety personnel said the recommendations are helpful but took too long to emerge.
"This project's been going for three years and it's just hitting the front lines," said Ohio safety consultant Ken Trump. "We needed to be reinforcing what we knew on the front line the day after Columbine."
Duane Hodgin, an assistant superintendent with the Metropolitan School District of Lawrence Township in Indianapolis, said the district has had a "threat assessment procedure" for three years, requiring psychological evaluations of students whose threats seem serious.
"There is no one profile, but ... there are indicators that you have to look at," he said. "You have to use common sense."
Nonetheless, Hodgin said he would attend a training session this summer.
"We want to get all the training, awareness, anything we can to keep our students, staff, everybody as safe as possible," he said.
By Greg Toppo