FBI leaders and local law enforcement officials are studying shootings in schools to piece together trends and come up with ways to prevent future violence, officials said.
The FBI on Wednesday hosted a daylong session at its headquarters to discuss common warning signs of shooters, information sharing among law enforcement and response plans among schools.
"We can't allow ourselves to become numb to it," Josh Skule, the FBI's executive assistant director for intelligence, said in an interview. "We just cannot think that this is an acceptable way to live our lives, and so however this topic stays at the forefront so that folks continue to talk about ... is critical to mitigating the threat."
The session comes on the heels of deadly school shootings like the February attack in Parkland, Florida, that killed 17 and the one in Santa Fe, Texas, last month that claimed 10 lives. Those shootings are part of what officials described as an alarming increase in the number of mass shootings, though the reasons for the uptick are still being debated.
"The active shooter threat is here to stay," said FBI Deputy Director David Bowdich. "I wish it wasn't. I wish it was a passing phase."
On Wednesday, the FBI shared the findings of recent research into 63 active shooters. The research showed that most, 77 percent, had spent a week or longer planning their attack and that many of them had shown multiple signs of warning behavior in the year before the violence. The FBI said it could verify that 25 percent of the shooters who were studied had been previously diagnosed with a mental illness.
Among the speakers was Max Schachter, whose 14-year-old son was among the victims of the Marjory Stoneman Douglas High School shooting in Florida and who has since dedicated himself to lobbying for improvements to school safety.
"After the shooting, just trying to deal with my grief, I was just incensed that Alex was killed because this monster shot right through the glass and he never went into the classrooms," Schachter said in an interview, speaking of the suspect in that case, Nikolas Cruz. "I just didn't understand why the schools were so unsafe and tried to figure out what I could to make them safe."
The FBI has acknowledged that it failed to follow up on information about Cruz received by a bureau tip line before the shooting. The handling of that episode remains under investigation, and the FBI is working on a report, Skule said.