At the entrance to Sidney High School in small-town Ohio, there is a poster which reads: "Inside this building, our children are protected by an armed and trained response team."
In rural Shelby County, law enforcement trained some teachers to fight back, should an attacker threaten students. They were among the first in the United States to embrace the controversial strategy.
On Halloween, as high school students and staff roam the hallways, John Pence -- a firearm on his belt -- patrols calmly.
He is a full-time resource officer, assigned to ensure security at Sidney High. That arrangement has become commonplace across the country, as the number of school shootings has multiplied.
But he has back-up: the response team of armed teachers, who have volunteered for the job.
So far, about 15 US states have approved similar set-ups, but many are not happy about putting weapons in the hands of educators.
Pence rejects the usual arguments, saying: "In some areas, probably it might not work -- maybe in a city. But most of these employees have been exposed to some type of firearms training beforehand."
One Sidney teacher, who cannot be named in order to protect the confidential nature of the armed response team, is indeed one such case. He is an avid hunter.
He says he had "no fears, no hesitations" about joining the effort to safeguard the school -- even if that means that one day, he could find himself faced with the prospect of shooting at one of his students.
"That's one of those boxes that mentally you can have to check," he told AFP.
"I have a wife and I have kids so if anybody is going to try to do any harm to them, this is what I'm going to do -- this is what has to be done if it's a student that is causing the threat.
"The other students being threatened, they have the right to go home to their parents that night too."
- A death every 17 seconds -
The idea of arming teachers -- the "program" as those in Sidney call it -- first surfaced after the Newtown shooting in 2012, in which 26 people, including 20 children, were killed at Sandy Hook elementary school.
The shooter also shot and killed his mother before taking his own life.
After that horrific attack, Shelby County Sheriff John Lenhart says he realized how vulnerable the schools in his area were.
He pushed for new safety measures as he contemplated a hard truth: "The rule of thumb is after the first shot is fired, every 17 seconds after that, somebody dies. So you need an immediate response."
But he never suggested that teachers should give lessons or patrol the hallways with a firearm on their hips.
"I didn't want our schools to look like the Wild Wild West, like an armed fortress," said Lenhart, who sports a thin white mustache.
The response team has access to 9mm Glock pistols, which are kept -- along with the ammunition -- in small black safes that only open when the digital fingerprint of an authorized user is scanned.
Bob Humble, the superintendent of Sidney's school district, which accounts for 3,500 students in six buildings, is proud of being a trailblazer.
He thinks that in addition to ensuring a quick response in case of an emergency, the team offers a compelling deterrent to any "crazy people with guns."
"Their goal is to get the highest body count they can in the shortest amount of time," Humble says.
"This is why I think the chances of this happening are very low now, simply because they know someone's going to take them down in a hurry."
For Humble, having such a security team "is just common sense."
"The kids don't think anything about it. You can't really hear anyone talking about it -- it's just embedded into the community now."
- 'It makes me feel safe' -
At the end of the school day, parents, grandparents and babysitters sit in an orderly line of cars, waiting to retrieve their young charges.
David Bishop, who is picking up his granddaughter, says the armed response team at Sidney High is fine with him.
"My grandaughter, she knows how to handle a gun," he says.
"Her brother and dad have guns, her mother too. She's too young yet, but they have taught her how to respect a gun and how to use it if needed."
High school senior Tom, who is 18 and asked that his last name not be revealed, said students hardly talk about the "program" in their free time.
"We all know the weapons are there, but it doesn't really concern us. I know they are locked up in a safe -- the kids can't get them," he says.
The young man casually says he has faith in the teachers to protect him.
"I like the idea. It makes me feel safe because I know they are specially trained if an intruder comes in and they are able to stop him," Tom explains.
Before being invited to join the program, teachers are vetted in "serious interviews" and their criminal records are checked, Lenhart says.
After an initial 20 hours of training given by police, teachers go through refresher courses once a month.
"I'm very confident that our schools are some of the safest in the nation," Lenhart says.
The teacher who is part of the response team says he believes the vetting process is airtight, so the team can be trusted.
As an example, he explains that a few years ago, two teachers on staff were going through a divorce.
The male teacher was immediately removed from the "program" and his access to the safes revoked while his personal life was in turmoil.
Guns in fingerprint-activated safes are placed in designated classrooms around Sidney High School in the US state of Ohio for a response team of teachers to use in case of an active shooter
A trained and armed Sidney High School teacher, who keeps his identity concealed as part of the program, holds a walkie-talkie to be used for communication in case an active shooter threatens the school
Students sit in class at Sidney High School
Video cameras monitor the halls of Sidney High School