It's understandable that Pinellas Sheriff Bob Gualtieri has changed his mind and now supports arming more school personnel — including some teachers — to try to reduce the deaths in future school shootings. As chairman of the state commission investigating the massacre at Marjory Stoneman Douglas High in Parkland, Gualtieri has meticulously reviewed how that day unfolded and concluded fewer people may have died if some school staffers had been armed. But there are other ways with broader public support to prevent school shootings or reduce the death tolls.

Gualtieri met with the Times editorial board recently to explain his change in thinking. He refers to the kids who died by their first names and knows precisely where they were. He can trace the actions of the teachers who pulled students to safety or tried to help and were killed. From that seven-month study of the shooting (and the emotional impact of watching it unfold on video), Gualtieri came to his new position. Before, he thought only sworn law enforcement officers should carry weapons on campus. Now, he thinks well-trained, carefully screened, armed school personnel could be in the best position to stop an active shooter. It's an informed opinion driven not by ideology but by what he has learned about those deadly minutes at Douglas High.

Authorities say former student Nikolas Cruz began shooting on the first floor of a crowded classroom building. One teacher who was shot in the legs dragged himself to a safe corner. As Cruz continued down the hallway spraying bullets, Gualtieri suggests that wounded teacher, had he been armed, could have shot Cruz and stopped the killing. Instead, Cruz reached the wounded man and executed him, then headed for the stairwell in search of more victims. Cruz stopped five times to reload his AR-15 rifle — five opportunities, Gualtieri says, that someone with a gun could have stopped him.

But it wasn't a shortage of good guys with guns that allowed the Parkland death toll to reach 17. There was a cascade of failures. Cruz's issues were mishandled by the school district months before the shooting. Campus monitors saw Cruz entering campus carrying a rifle bag and failed to sound the alarm. Even if they had, they didn't have access to the school's public address system, and that system didn't broadcast in common areas or hallways. An armed school resource officer heard the shots but did not enter the building. Police agencies did not effectively communicate with each other.

Outfitting schools with communications systems that alert everyone on campus of danger is one obvious improvement. Even now, the commission has found school districts resistant to change. Some don't take seriously the need for every school to have a behavioral threat assessment team to identify students showing concerning behavior, as state law now requires. The team at Douglas High had done exactly one assessment, and it was on Cruz, but no one followed up. Even the simple precaution of identifying, marking and keeping clear the safest corner in every classroom wasn't done, and three students died in Parkland because they couldn't get to that safe spot. That's a staggering lapse that should never be repeated at any school, anywhere.

When lawmakers established the school guardian program this spring in response to Parkland, most school districts rejected the idea of arming school employees or used the money to hire armed security guards. While Gualtieri is to be commended for his leadership and dedication to finding solutions, expanding on an unpopular program is not the answer. Allowing more guns in schools risks myriad unintended consequences such police mistaking an armed teacher for an active shooter, unjustified shootings unrelated to armed intruders and accidental shootings.

The Parkland commission meets this week and could vote on whether to recommend arming more school employees as Gualtieri suggests. But rather than invite those risks, the focus should be on more practical solutions such as improved communication systems and hardened classrooms, better identifying troubled students and changing the culture in schools to embrace basic precautions.