The school board decided that teachers with concealed guns were a better form of security than armed peace officers, since an attacker would not know whom to shoot first, Mr. Thweatt said. Teachers have received training from a private security consultant and will use special ammunition designed to prevent ricocheting, he added.

Harrold, about 180 miles northwest of Dallas, is a far cry from the giant districts in major Texas cities, where gang violence is the main concern and most schools have their own police forces. Barely 100 students of all ages attend classes here in two brick buildings built more than 60 years ago. There are two dozen teachers, a handful of buses and a football field bordered by crops.

Yet the town is not isolated in rustic peace, supporters of the plan point out. A four-lane highway runs through town, bringing with it a river of humanity, including criminals, they say. The police recently shut down a drug-producing laboratory in a ramshackle house near school property. Drifters sometimes sleep under the overpass.

“I’m not exactly paranoid,” Mr. Thweatt said. “I like to consider myself prepared.”

Some residents and parents, however, think Mr. Thweatt may be overstating the threat. Many say they rarely lock their doors, much less worry about random drifters with pistols running amok at the school. Longtime residents were hard-pressed to recall a single violent incident there.

Others worry that introducing guns into the classroom might create more problems than it solved. A teacher tussling with a student could lose control of a weapon, or a gun might go off by accident, they said.

“I don’t think there is a place in the school whatsoever for a gun unless you have a police officer in there,” said Bobby G. Brown, a farmer and former school board chairman whose two sons were educated at the school. “I don’t care how much training they have.”

Image Harrold School Superintendent David Thweatt pushed for the policy to arm teachers with concealed guns. "Country people are take-care-of-yourself people." Credit... Rex Curry for The New York Times

His wife, Diane Brown, added: “There are too many things that could happen. They are not trained to make life-and-death-situation judgments.”