“We can never be over-prepared,” Norman said. “But we were prepared.”

His school board approved a plan in November to allow some school staff members to carry guns, joining more than 170 school districts in Texas that have made similar plans. But Santa Fe was still working on it, Norman said. People needed to be trained. Details needed to be worked out, such as a requirement that school guns fire only frangible bullets, which break into small pieces and are unlikely to pass through victims, as a way to limit the danger to innocent students.

All of these efforts, Norman said, are “only a way to mitigate what is happening.”