Since January, 50 people have been killed and 122 injured in at least 152 incidents of gunfire on school grounds across the U.S. To respond to the threat of such attacks, some districts — in at least 29 states that allow it — have taken the controversial step of authorizing school staff, other than security guards, to carry firearms on campus.In the aftermath of the shooting in Uvalde that killed 19 children and two teachers, Texas Republicans have urged schools to arm up and "harden the target."But Texas state laws regulating armed staff are sparing, allowing school districts to decide for themselves the type, and amount, of training school staff need 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 teacher in Rankin, Texas, who is authorized to carry a gun on his school's campus.Two weeks after the Uvalde shooting, the Texas American Federation of Teachers conducted a survey of 5,100 Texans, 4,673 being school employees."