REDWOOD SHORES -- A lot has changed since a high school dropout launched a bomb attack in 2009 on his former teachers in San Mateo.

Though the assault on Hillsdale High School was halted before anyone was hurt, a string of mass killings carried out since -- most notoriously the fatal shooting of 20 first-graders and six adults at a school in Newtown, Conn. -- have forced parents and officials to confront the possibility it could happen in their town.

That threat has prompted San Mateo County community leaders to hold a first-of-its-kind summit on Monday, bringing together educators, police, mental health workers and politicians to discuss how they can work together to prevent another, costlier attack here. The summit -- "Beyond Newtown: How to Ensure Safe Schools and Communities" -- will feature a nationally recognized expert on school violence.

Rampage

Alex Youshock, then 17, convinced his mom to drop him off near Hillsdale High School the morning of Aug. 24, 2009, for what he claimed was a video shoot with a friend. What his mother didn't know was that inside a guitar case and backpack Youshock carried 10 homemade bombs, a small samurai sword and a chainsaw.

After setting off two bombs inside the school, which hurt no one, Youshock was tackled by a teacher and subsequently arrested. Investigators later discovered a video manifesto and writings that indicated Youshock planned to kill three teachers he felt had wronged him. After he was convicted of charges stemming from the attack, Youshock was committed to a state mental hospital.

Katherine Newman, dean of arts and sciences at Johns Hopkins University, will be the keynote speaker at Monday's summit and has recommendations for detecting the plans of young men similar to Youshock. The Mills High School graduate is the lead author of "Rampage: The Social Roots of School Shooting," a 2004 book that delves deeply into two pre-Columbine school massacres in Arkansas and Kentucky.

Evidence piling up

Newman said her research, which included interviews with more than 160 people, showed warning signs were being missed. The shooters weren't loners, and their plans weren't a secret to everyone. The killings weren't happening in big cities, but rather in stifling small towns and suburbs. Behavior problems and teachers' concerns weren't getting transmitted from one school year to the next. Also, the shooters were suffering from varying types of mental illness.

"There was a lot of evidence piling up and nobody was seeing," she said.

While people are more sensitive to school violence threats than in the 1990s -- as "lockdown" and "school massacre" have become part of the common lexicon -- her conclusions are still instructive. Newman said schools need to focus on intercepting warnings by letting kids know they have a moral imperative to come forward with tips. But schools also need to have people with whom kids can share this type of sensitive information.

"We were big fans of school resource officers," said Newman, referring to police who work in schools.

Their usefulness is not in responding to the violence, which quickly results in lots of damage. Instead, the officers have relationships with the kids, but they are seen as apart from the school authority structure of discipline. The students are less afraid to be frank with them, Newman said.

Working together

The summit Monday at the Oracle Conference Center in Redwood Shores is co-sponsored by Rep. Jackie Speier, D-Hillsborough. While it will not be open to the public, the participants hope it will be a useful jumping-off point for police, schools and mental health experts to work together on the evolving issue of rampage violence. San Mateo County School Superintendent Anne Campbell said schools' primary response has been to keep students locked in classrooms during an attack. But she said there's discussion of moving the kids away from danger.

"Perhaps we don't have one way to respond to something like this," Campbell said. "We need to be multifaceted."

Also, the collection of more than a dozen, closely packed cities on the Peninsula necessitates a common plan across borders, said San Mateo police Chief Susan Manheimer. If something big happens police are going to come from around the county, and the summit is a chance to start planning together.

"All of the different law enforcement and school systems need to be coordinated," she said.

Contact Joshua Melvin at 650-348-4335. Follow him at Twitter.com/melvinreport.