Since the U.S. Senate refuses to consider any regulation of guns, some schools are preparing for the next shooter.

In Colorado, students are receiving training in how to respond if they are confronted by an active shooter.

Colorado was the site of the Columbine massacre in a high school and the Aurora massacre in a movie theater. Last May, a student was killed in a charter school in Douglas County.

The gym at Pinnacle High School echoed with laughter and a few cheers Wednesday morning as students took turns tackling a heavily padded man.

While it might have sounded like a game, the orange water pistol in the demonstrator’s hand served as a reminder of what would be at stake if they ever had to use the tactics they were learning on a real assailant.

The Adams County K-12 charter school spent most of the school day having students practice skills such as barricading their classrooms, evacuating the building — and, if necessary, defending themselves. Many schools near Denver and across the country teach the idea of fighting back as one possible option during an attack, but relatively few have students actually practice what they might do if a gunman entered their classrooms.

Clarissa Burklund, president of Pinnacle’s school board, said officials hadn’t discussed having students do more than traditional lockdown drills until this summer. The May 7 shooting at STEM School Highlands Ranch, where three students rushed one of two attackers, showed that teenagers could defend themselves and need to prepare for that possibility, she said.

“I hate that they have to talk about this,” she said with a catch in her voice. “I hate that they live in this society. But they do, and there’s no point in denying it….”

There’s no nationwide tracking of how schools prepare their students for active shooters, but emphasis appears to have gradually shifted from “locks, lights, out of sight,” where students are told to take shelter in their classrooms, to “run, hide, fight,” where they are expected to choose their best option for the situation. Some schools also have started conducting more realistic drills, including the sounds of simulated gunfire, but that practice has spurred controversy, especially when students weren’t aware they were only dealing with a drill.

Little evidence exists to show if one type of active shooter training is more effective than another, and some experts have concerns about emphasizing cases in which students have fought back. The fear is that could encourage students to overlook safer options such as evacuating.