Police tape surrounds Great Mills High School after a shooting at the Southern Maryland campus Tuesday. (Jonathan Newton/The Washington Post)

On Oct. 2, 2006, a dairy truck driver well-known to the Amish community of Nickel Mines, Pa., walked into its one-room schoolhouse, took hostages and, in about a half-hour, shot and killed five children, wounded five others and killed himself. The news alarmed me: As the superintendent of a small, rural district with only one campus, I recognized that West Nickel Mines school could have easily been my school, and those killed could have been my students — my kids.

So, at the Harrold Independent School District, we decided to do something about it. We allowed certain faculty and staff to carry concealed firearms on school grounds, during school hours. Our students are safer for it.

School shootings aren’t new, but in recent years they’ve become more deadly. Cause and effect are often hard to determine — we never know why people do evil things. But I believe one reason that schools remain vulnerable is the misguided Gun-Free School Zones Act of 1990. Even though the Supreme Court ruled it unconstitutional in 1995, an amended version lives on. Our most valued asset — our children — have been left unprotected in their own schools.

After the Nickel Mines shooting, I contacted our school attorneys to determine if my Guardian Plan would be legal on the state and federal levels. The program was simple: The school board would individually approve school employees who already held state concealed handgun licenses to participate in the program, and the district would provide them with extra training. (In 2007, the district engaged a private consultant to develop additional training; in 2013, I worked with the Texas legislature to develop and pass Senate Bill 1857, which created a school safety certification course that could be utilized by schools opting to employ programs similar to ours. Harrold ISD Guardians are scheduled to complete this certification in the near future.) The names of our Guardians are kept confidential, and they are paid a small yearly stipend in addition to their regular salaries to have them carry concealed handguns at school.

[I’m a Broward County teacher. Thoughts and prayers won’t keep my students safe.]

By December 2006, we had the answer from our attorneys — the plan was legal under federal and state law: 18 U.S.C. § 922 (q)(2)(B)(ii) permits possession of a firearm on campus if the individual possessing the firearm “is licensed to do so by the State in which the school zone is located.” Texas Penal Code § 46.03(a)(1) makes it an offense for an individual to possess a firearm on school grounds except “pursuant to written regulations or written authorization of the institution.”

But our school board was reluctant to move forward. The members didn’t question the plan’s merits, but there was concern the idea would be construed outside of our community, perhaps in the media, as being too far outside the box.

Several months later, though, the district’s reluctance turned to resolve when the Virginia Tech shooter wounded 17 and killed 33, including himself, with two handguns — one .22-caliber and one 9mm. In our district, we were convinced that if someone had been armed with a concealed handgun, and had been in a position to confront that shooter, that story would have ended differently. Perhaps more important, we believed that if the shooter had thought it likely, or even just possible, that someone might be there to return fire, he would have been hesitant to move forward with his atrocious plan. Being able to retaliate during an ongoing attack is crucial. Prevention is preferred.

The participants’ anonymity is key to our program; no one in the general public knows the identity of the Guardian Plan team members. We don’t release numbers, but at all times there is an armed school employee, or employees, on site. Experts note that mass-shooting perpetrators look for “soft” targets — places not protected by anyone who can effectively resist attack. If a person planning an assault knows that he may meet resistance, he’s less likely to attempt to attack that venue. In essence, the potential target has an insurance policy. The Guardian Plan doubles that policy. Not only will a shooter encounter resistance, he will not know from where and from whom that resistance will come. The common element of most mass shootings is surprise. Anonymity lets the Guardian Plan use surprise against the perpetrator.

As we know, “hard” targets like federal buildings have some means of resistance. Security guards, sheriff’s deputies or other similarly armed individuals are regularly employed at many schools. Often, they are limited in number, usually because of cost. The Guardian Plan simply grafts a modest stipend onto a current employee, giving the school district not only quality protection but also the financial flexibility to have multiple guards — that is, quantity, too.

By allowing a school to maximize its number of trained, armed staff, the Guardian Plan is a force-multiplier. Think of how schools are set up: They typically have long, branching corridors with rooms off those corridors. The buildings themselves create their own gun-silencing and incident siloing effect. If a school has one resource officer on site, and he or she is at one end of the school, it may not be feasible for that officer to detect, let alone respond in time to, a deadly threat. You need eyes and ears strategically placed throughout the school, and they need to be equipped to deal swiftly with a life-threatening attack. The Guardian Plan offers a speedy, concentrated and effective reaction. Seconds matter. (Area-wise, our county is about three-quarters of the size of Rhode Island, patrolled by a limited number of sheriff’s deputies. They are dedicated professionals, but they would not be able to make a speedy response to an attack.)

[How to protect yourself during a mass shooting]

Those opposed to this type of plan argue that allowing faculty and staff to carry concealed firearms makes schools more dangerous, not less. Yet many of those same people are okay with the status quo — uniformed, armed security guards carrying firearms on school campuses (not to mention airports, stadiums and malls) in open holsters. Their objection reflects a misunderstanding. The Guardian Plan is a permutation of the status quo, that’s all. A teacher will almost inevitably be closer to an attack than a security guard devoted to an entire campus.

Since threats must be confronted quickly, we shouldn’t limit who initiates the confrontation. Critics will point to the recent incident in California, in which a teacher accidentally discharged a firearm. But it’s more instructive to look at this week’s school shooting in Maryland, in which a school resource officer immediately confronted a shooter after two students were shot. What mattered was the response, and the response time.

There’s also the argument that educators already have too much to do, and aren’t qualified to take on this type of duty. After working in education for 38 years, I’ll be the first to say that not every school employee is cut out to carry a weapon or to act in a life and death emergency. But many are. And as the official ultimately tasked with protecting every student in the district, I wouldn’t have done my job if I didn’t give those employees every possible resource for protecting the kids in their charge.