In at least 152 incidents of gunfire on school grounds across the United States since January, 50 people have been killed and 122 have been injured. To combat the threat of such attacks, some school districts in at least 29 states that permit it have authorized school personnel other than security guards to carry firearms on campus. One of these states is Texas.

Following the Uvalde shooting that killed 19 children and two teachers, Texas Republicans have urged schools to arm themselves and “harden the target.” However, Texas state laws governing armed staff are lenient, allowing school districts to determine the type and amount of training required for school staff to carry guns on campus.

“I feel like as educators and coaches, we have an obligation to protect… other parents’ kids while they’re in our custody,” said Garret Avalos, a Rankin, Texas, teacher who is allowed to carry a gun on his school’s campus. “For me, it’s a no-brainer.”

According to the Texas Association of School Boards, under Texas Penal Code 46.03, “school districts can grant written permission for anyone, including designated employees, to carry firearms on campus,” but the law does not specify training requirements. A school employee only needs a license to carry a firearm on campus, which requires a background check and a proficiency demonstration. Individual districts, on the other hand, determine the amount and type of additional requirements, which can include active-shooter training courses and psychological evaluations.

These plans are commonly referred to as “guardian plans.” The Harrold Independent School District in Harrold, Texas, was reportedly the first in the state to adopt a plan resembling what is now known as a guardian plan in 2007. According to a Texas School Safety Center audit, as of 2020, 280 school districts out of 1,022 had adopted some form of one.

Jeff Sellers is the founder of Schools on Target, a company that provides firearm training to school staff through his Texas School Guardian Program. He told CBS News that for his program, he requires his trainees to shoot with 90% accuracy and log 40 hours of training before he will pass them, as well as the Minnesota Multiphasic Personality Inventory, a psychological evaluation commonly used to assess candidates for law enforcement. He then works with the school’s administrators to help them approve guardians after completing the course.

According to Sellers, teachers can be armed in schools without any training if the district so decides. However, he claims that the schools he works with do their best to implement comprehensive requirements.

“We’re working with educators,” Sellers explained. “Our clients are very intelligent people who are held accountable by boards.”

Despite these efforts to arm teachers, Sonali Rajan, a Columbia University school violence researcher, says there is no evidence that it makes schools safer.

“At the moment, there is no science available, absolutely none, that shows that arming teachers would either deter gun violence from occurring in the first place or would deter or reduce the lethality of a shooting once it occurred,” Rajan said. “There is evidence that clearly and unequivocally shows that increased firearm presence leads to increased firearm violence and firearm-related harms.”

Two weeks after the Uvalde shooting, the Texas American Federation of Teachers polled 5,100 Texans, 4,673 of whom were school employees. 76% of all respondents stated that they “do not want to be armed or expected to apprehend a gunman.”

But Sellers believes there is no other option.

“No gun control law will stop an evil person from committing an evil act,” he asserted. “If they don’t have guns, they’ll use knives, explosives, or a vehicle to get through a building. You will not be able to prevent evil from occurring.”