Missouri Gov. Jay Nixon vetoed a measure Monday that would have permitted certain educators to carry concealed weapons on school property.
Nixon, a Democrat, cited student safety in public schools as a reason for concern.
"Arming teachers will not make our schools safer," the governor said in a statement. "I have supported and will continue to support the use of duly authorized law enforcement officers employed as school resource officers, but I cannot condone putting firearms in the hands of educators who should be focused on teaching our kids."
The measure would have allowed teachers to become "school protection officers," according to the governor's office.
"This bill, which would create a new mechanism for the arming of teachers, would not make schools safer," added Nixon, who is also a former chief law enforcement officer in Missouri.
Monday was the final day Nixon was expected to take action on measures passed earlier in the year. But the legislation could survive if the Republican-led state legislature revokes Nixon's temporary ban on the bill with a two-thirds vote in the House and Senate during a September session.
Some districts believe schools need armed teachers because they think law enforcement takes too long to respond to emergencies.
In the wake of school shootings across the country, some school board members sent voluntary faculty to a concealed-weapons training. At least 10 districts across Missouri have completed the instruction in the past 18 months.
Districts in other states – including Kansas, Ohio and Indiana – have also demonstrated interest in the training.
Ninety-one percent of teachers said they believe an armed guard would improve school safety at least somewhat, according to a membership poll published earlier this year by the Association of American Educators. Additionally, 75% of the surveyed members feel safe or very safe in their schools. About 20% of the organization’s 20,000 members responded to the survey.