Florida Gov. Rick Scott announced last week that the state would invest $500 million to protect its schools with metal detectors, bulletproof glass, steel doors and upgraded locks. But that's just part of the buildup of school safety measures that was underway even before the Parkland shooting — everything from lockdown drills to bulletproof backpacks and even bulletproof shelters in the schools.
The bottom line: Parents and officials are scrambling to find ways to protect students in an era that's endured 273 school shootings since Newtown. The Parkland shooting is intensifying the debate over which safety measures really work.