What echoed like a symphony of wind chimes throughout a Commerce City shooting range was actually the sound of footsteps from Principal Robert Garrow and fellow Colorado teachers and school administrators as they blazed a trail through a sea of bullet casings.

The educators then each lined up in front of a target emblazoned with a torso and head, unholstered their guns, aimed and fired at what represented a school shooter they were being trained to kill.

On day two of a three-day training session preparing Colorado teachers and school administrators for being armed in the classroom, one trainee asked how he would know what to do if he and multiple teachers pulled their guns on a “bad guy.” The trainee worried crossfire could injure innocent students when the intent was to save lives.

Quinn Cunningham, a local SWAT and law enforcement officer passionate about instructing teachers with concealed carry permits how to properly use their guns to kill a threat during an active shooting, responded with one word: “Training.”

Colorado is one of at least nine states where teachers may arm themselves in the classroom if their districts or charter schools allow it. Thirty school districts or charter schools in the state have done so — though which districts do is less clear. There is no statewide training standard for school employees who carry guns, no standard use-of-force policy like the kinds intended to advise police officers and little guidance for school districts other than what their liability insurers provide.

The result is that the arming of teachers in Colorado is a local issue not subject to debate, questioning or review by state regulators or lawmakers. That’s likely the way many rural districts prefer it, but even some ardent gun-rights supporters have sought a more uniform approach.

Republicans in the statehouse last year sponsored a bill that would have required school boards to consult with their county sheriff’s department to develop a curriculum for arming teachers. Senate Majority Leader Chris Holbert, a Parker Republican who co-sponsored the bill, noted training courses for teachers and other staff members can be minimal. He wanted his bill to establish and bolster training standards.

The bill didn’t make it out of committee in the Democrat-controlled House, where opponents feared it would lead to allowing more guns in schools.

Colorado doesn’t track where teachers are allowed to arm themselves, so The Denver Post reached out to each of the state’s 178 school districts and found that out of the 72 districts able to be reached during summer vacation, four said they allow teachers and staff to carry a concealed gun on campus. Two others have already said so publicly.

Those reached by The Post were Bennett School District, about 25 miles southeast of Denver International Airport; Sangre de Cristo School District in Mosca, about 20 miles west of Great Sand Dunes National Park and Preserve; Woodlin School District in Last Chance, about 85 miles east of Denver; and Weld County RE-1, a few miles south of Greeley. Those that have said they allow teachers to carry guns are Hanover School District about 30 miles southeast of Colorado Springs; and Frenchman School District in Fleming.

A district could refuse to answer whether they allow teachers and staff to arm themselves, citing security concerns, said Chris Harms, director of the Colorado Department of Public Safety’s School Safety Resource Center.

One El Paso County teacher who underwent armed school staff training isn’t hiding his desire to carry a gun during lessons.

John MacFarlane, a physics teacher at Rampart High School, said he got his concealed carry permit five years ago, later becoming a certified handgun instructor.

“I honestly walk into school every day … and think I hope I don’t get killed today,” MacFarlane said. “If I was carrying, I would think I hope I don’t get killed today, but at least I have a fighting chance of not dying.”

MacFarlane’s district, Academy School District No. 20, doesn’t allow teachers to be armed. The physics teacher said he understands the issue is sensitive and divisive, but he feels patronized by school officials who won’t hear him out on the subject simply because it’s taboo.

“Most teachers are the last people I want anywhere near a gun, but there are a very small minority of us who are very competent and have the right mindset to assist security if there was some sort of active shooter situation,” MacFarlane said. “We should have people like me who know guns, know training and have worked with people in law enforcement and security all working together to come up with solutions.”

The entity in the state coming up with the most regulated training and solutions for arming educators is an insurance company.

The Colorado School Districts Self Insurance Pool, the leading state insurer of school districts, insures a combination of 30 districts and charter schools that have approved teachers and staff arming themselves. The insurance company knows which districts, charters and individual teachers and staff are allowed to carry guns during the school day, but the information is not for public knowledge.

“We’re sensitive about not creating records that could disclose this,” said Craig Hein, the insurance company’s general counsel.

No one in the state has a comprehensive understanding of which school districts let their teachers carry or what consistent policies exist to regulate when a teacher can justifiably pull the trigger.

“There isn’t a lot of information,” said Harms, with the state department of public safety. “I can’t tell you which districts do, either, because I don’t know.”

Because Colorado’s education system operates under local control, school boards and charter schools decide whether arming teachers makes sense for their communities.

“It’s not problematic because we’re a local control state,” Harms said. “When you think about it, what would it matter other than to the insurance companies? If the district has made that decision and the insurance company is covering them and the local law enforcement are on board, I don’t think it’s necessary for others to know.”

Based on Colorado law, school boards could designate teachers and staff as school security officers permitted to carry a concealed weapon on campus without ensuring training.

But the teachers, schools and districts insured through the insurance pool must meet certain requirements. Those include:

Armed teachers and staff must comply with local and state requirements to carry a weapon;

They must complete a minimum of 24 hours of firearms training within the last 12 months;

The training must include four hours of classroom instruction on “firearms safety, use of deadly force, legal principles and weapons retention in a school environment” and 14 hours of live firing range training exercises including active shooter training;

Participants must pass Peace Officer Standards and Training-equivalent shooting range requirements, which is the shooting range test police officers must pass; and

They must complete six hours of school active shooter training including classroom time and simulated training.

To requalify each year, teachers and staff must complete a minimum of 16 hours of training and gun equipment should be standardized among school personnel.

The company collects documentation districts provide showing the requirements have been met. The insurance company does not otherwise check to make sure the schools are compliant.

CSDSIP recommends training or training protocols reviewed by a “credentialed, objective third party.”

One route for completing the training is the Ohio-based active school shooting training, Faculty/Administrator Safety Training and Emergency Response (FASTER) program, that has made its way to Colorado.

Most of the nearly two dozen teachers and school staff attending a June training through FASTER didn’t want to be identified.

Some worried about making themselves targets during a school shooting. Others said they couldn’t bear to think of their students who look to them for academic and emotional nurturing discovering they were carrying a gun.

The FASTER training unfolded at Flatrock Regional Training Center down a gravel road in Commerce City. The facility that trains law enforcement cadets around the state is home to two tactical firearms ranges and a simulator room where teachers experience a virtual reality school shooting. The 399-acre center also has classrooms where law enforcement instructors discuss details about active shootings they’ve responded to. Part of the lesson includes combat-style medical training.

Instructor Cunningham responded to the 2013 Arapahoe High School shooting in which 17-year-old Claire Davis was killed.

“I couldn’t give my life for her that day, so I decided to give every day of my life to start giving people the training they needed to save lives,” Cunningham said.

Because Cunningham is a FASTER instructor, he said he isn’t allowed to disclose which law enforcement agency he works for.

Cunningham points to the Arapahoe incident, where a student died despite a law enforcement-sanctioned school resource officer in the building, as evidence why arming willing, trained teachers is necessary.

“When somebody goes into a school with a gun, the only thing that’s going to stop them is somebody else with a gun,” Cunningham said.

The portion of FASTER’s three-day training Cunningham considers most important is getting teachers in the mindset to possibly take someone’s life — maybe the life of a student-turned-shooter they’ve taught in their own classroom.

The mental part of the training, Cunningham said, includes simulations and visualizations like trainees imagining a shooter in the school with kids screaming. Trainees watch video re-enactments of school shootings, learn shooting techniques and shoot each other with replica guns.

“They need to see what they might have to encounter,” Cunningham said.

A veteran police chief who has served in Colorado Springs thinks caring teachers should back away from bringing guns into classrooms.

Rick Myers is the executive director of the Major Cities Chief Association, a professional organization of police officials representing the largest cities in the U.S. and Canada.

Myers, who’s been in law enforcement for 41 years and was a Colorado Springs police chief for five of those, was troubled after reading about armed teacher trainings in Colorado.

Police officers, Myers argued, receive hundreds of hours of training in areas like knowing when to shoot, shot placement, sizing up an environment and shooting while avoiding hitting innocent people.

“None of that is possible in the short duration they’re giving teachers and saying it’s OK to give them arms in schools,” Myers said. “The thought of our most precious resource, the children, being in a secure area with someone armed with deadly force but not received the same level of police officer training is somewhat frightening to me.”

Some trainees out on the Flatrock gun range were corrected for putting their fingers on the trigger too early during shooting practice. Others seemed more relaxed behind their weapons, prompting Laura Carno, co-founder of Coloradans for Civil Liberties who brought the FASTER program to the state, to note that many participants have former law enforcement or military backgrounds.

Sixty-seven trainees, mostly school employees, have gone through FASTER training in Colorado with another full class expected for August.

A June batch of FASTER trainees, a group of mostly men and a few women, practiced shooting around barrels to mimic taking cover. The trainees dropped to their knees and bellies for practice firing from different vantage points. They shot while taking short, quick steps to practice pulling the trigger while on the move.

Garrow, who led a Jefferson County charter school he didn’t want to identify, was exploring the idea of arming teachers at his school. The principal said he keeps his daughters, who will soon be attending the school, in mind when thinking about the issue.

“We want to be in the best position possible to protect our students,” Garrow said. “Parents put us in a position of trust over their children, and we want to do right by them. There are things that happen that you need to be prepared for as best you can be.”

Garrow noted arming teachers wasn’t the only solution schools needed to start considering. Training teachers and staff on proper medical care was important, he said, and fostering a school culture that prioritized responsibility and friendship.

Rural school leaders like Sangre de Cristo Superintendent Brady Stagner worried no matter what culture they created, their schools were still 20 minutes away from police if the worst happened.

Stagner’s school board voted to allow employees to be armed last August. The superintendent said the district lets parents know that non-law-enforcement individuals are carrying guns on campus.

While Stagner said Sangre de Cristo doesn’t have a specific policy on what would happen if a teacher shot a student, he added that the district follows the insurance pool standards and that it would be acceptable for a teacher to pull the trigger “when the threat is present and doing harm.”

Instructors with FASTER say students are taught Colorado law about use of lethal force.

Mike Kaiser, a community policing specialist with the Adams County Sheriff’s Office, said a teacher’s gun use would be treated like any other use of force case if a citizen shot someone on the street. Kaiser said state law allows for protection of your own person or a third party and that a specific use of force policy for armed teachers doesn’t exist yet, to his knowledge.

Safety professional Myers had just wrapped up with a school safety summit held at FBI headquarters in Washington, D.C., when he told The Denver Post his concerns about Colorado’s armed teacher policies.

Myers thought the lack of a standardized use-of-force policy for teachers given authority to use deadly force in the classroom could be problematic.

“The problems aren’t going to be any different in a police department when you do have a consistent use-of-force policy,” Myers said. “How often does a police officer use force up to and including deadly force that some in the community questions the appropriateness of? And that’s after hundreds and hundreds of hours of training.”

Myers conjured a scenario where a high school student experiencing a mental health episode became violent and started throwing desks.

“A teacher might be armed and say they don’t see any other alternative than to use deadly force,” Myers said. “All they need to do is articulate that they fear for their life.”

Staff writers Chaney Skilling and Natalie Weber contributed to this report.