Teachers, it is said, have some of the hardest jobs in the world. The hours are long, and the rewards often intangible. In addition to designing and executing lesson plans, grading homework and coordinating extracurricular activities, teachers are expected to be surrogate parents, offering children personal comfort and protection over the course of a long school day.

In recent years, teachers have also had to contend with a devastating reality: the increasing threat of school shootings.

While gun violence in the U.S. has significantly declined since the 1990s, mass public shootings are on the rise, and schools are now viewed as vulnerable targets. One of the deadliest in history claimed 28 lives, including 20 children, after Adam Lanza opened fire at Sandy Hook Elementary School in Newtown, Conn., in 2012.

Last October, a gunman fatally shot nine people at Umpqua Community College in Roseburg, Ore.

These incidents, and every school shooting in between, have sent mourning parents and distraught education officials on a search for effective preventative measures.

One that has long been bandied about, and now being tested in schools countrywide, is allowing teachers to bring guns to school.

The Kingsburg Joint Union High School District in Kingsburg, Calif., is the latest district to pass such a measure. At a school board meeting on Monday, the Fresno Bee reported, members unanimously approved a policy that allows district employees to carry a concealed firearm within school bounds.

The employees will be selected by the superintendent, and will have to complete a training and evaluation process. The new policy was made effective immediately.

While proposals to arm teachers have been familiar refrains in Texas and Indiana, the passing of such a mandate on the West Coast signals that the strategy is being considered elsewhere in the country.

In fact, the Folsom Cordova Unified School District covering the cities of Folsom, Rancho Cordova and Mather, Calif., has allowed teachers to bring guns to school since 2010, but only revealed the policy to parents last month.

“Our narrow practice of allowing select, law-abiding employees to securely store and access a firearm in the event of an emergency is a legal and appropriate safety measure given the unfortunate reality of violence in our society today,” superintendent Deborah Bettencourt said in a letter to parents, according to the Los Angeles Times.

The Folsom Cordova policy is more rigid than the newly-adopted one in Kingsburg, as the latter allows teachers to carry guns in a holster as opposed to simply storing them in vaults.

Like the Folsom Cordova policy, however, Kingsburg’s emphasis is on giving teachers the resources to protect their students – and possibly prevent a Sandy Hook-scale tragedy.

Reactions to Monday’s vote have been mixed, with some parents expressing concern about how the presence of guns will change an otherwise relaxed school environment, where there are no surrounding fences or police officers.

Mary Lou Swenning, whose grandchildren attend schools in the district, told the Fresno Bee that she was worried about the burden guns could place on teachers. She called the policy akin to measures out of the “Wild West.”

“Now we’re going to add something else for teachers to think about?” Swenning asked. “Shooting people, really? That’s a difficult thing for a police officer to do who’s been trained to do this, and you have a split second to decide if you should kill this person or not. I wouldn’t want that responsibility, and I wouldn’t want it for our teachers.”

Whether parents want it or not, similar policies have already been adopted in Oklahoma, Ohio, Utah and other states. Many school districts cite the shooting at Sandy Hook as the kind of event that they hope armed teachers could prevent.

Kasey Hansen, a special needs teacher in Salt Lake County, Utah, told NBC News in 2014 that she carried her pink handgun “Lucy” every day.

“I never really thought about it before Sandy Hook,” Hansen said. “I think every teacher should carry. We are the first line of defense. Someone is going to call the cops and they are going to be informed, but how long is it going to take for them to get to the school?”

On the other hand, a teacher was arrested earlier this month for bringing a concealed firearm into Newtown Middle School, located in the same town as Sandy Hook.

The incident was “very serious and troubling,” the Newtown Public School system said in a statement.

(c) 2016, The Washington Post · Yanan Wang