Educators learned that it would be about 10 minutes before any police arrived and that what they needed most in those first few critical minutes was a plan - and backup plans.
Law enforcement officials said the three fundamental responses come down to: "Evacuate. Hide out. Take action."
Lou Gentile, director of public safety for the Upper Darby School District, cautioned the educators against denying the possibility of an attack.
"If you don't think it is going to happen, how can you mitigate it?" Gentile said.
Educators were told that they are the first line of defense to prevent a school shooting. Teachers and school officials need to recognize threats, which can begin in the virtual world; communicate warning signs; and trust the judicial system, which exists to protect victims as well as the accused.
Unfortunately, said FBI Special Agent Joseph Metzinger, the signs of a potentially violent student are not always detectable. "There is no one profile," he said. "What we look for on our side is behavior."
He advised watching for signs that include evidence of feelings of isolation, that everyone is against a student; increased absenteeism; fascination with previous attacks; destruction of property; physical changes; and increased absenteeism. Has a student suffered a recent trauma or disappointment, lost a parent through death or divorce, or lost a job, or failed to make a team?
The challenge for educators is to distinguish potential indicators of violence from those of a teen having a bad day or month.
"Always err on the side of caution," said Upper Darby Police Sgt. James F. Reif, a panelist. He told members of the audience that when in doubt about whether to contact police, make the call.
Participants were given a checklist that included sign-in procedures, video surveillance, adequate lighting, window locks, on-site communication, emergency plans, and staff training.
The conference was not all about sitting and listening.
Attendees got an up-close look at a $250,000 mobile police robot - nicknamed Wile E. - that comes with cameras, microphones, and water guns that can put a hole in a car door or destroy a window.
Then came the big question: how to mine scant funds for security improvements. Panelists suggested turning to the county for money or phasing in the needed changes.
"You hate to put a dollar signs on a child's life, but it all comes down to money," said Phyllis Floyd, a school board member in the Interboro School District. "All these suggestions cost money. Where are school boards supposed to find the money when the state is cutting funding to basic education?"
Contact Mari A. Schaefer at 610-313-8111, firstname.lastname@example.org or @MariSchaefer on Twitter.