DENVER — The Douglas County Schools Superintendent laid down an ultimatum on school security Tuesday, saying that charter schools that arm teachers aren’t welcome in his district.

Dr. Thomas Tucker issued the warning while testifying before the state legislature’s School Safety Committee.

“We will fight tooth and nail, if any school, whether it's a neighborhood school or a charter school, decides to arm its teachers,” Tucker said. “If it's a charter school, we're going to ask that they leave the Douglas County School District oversight.”

A neighborhood school would need district permission to arm teachers. Charter schools are semi-autonomous and operate under contracts with local school districts or the Colorado Charter School Institute.

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Laura Carno, Colorado’s best-known advocate for arming teachers, said this was the first time she’d heard Douglas County Schools would try to cut ties with charter schools that allow teachers to carry weapons.

Carno’s organization, FASTER Colorado, provides training for teachers interested in carrying guns in the classroom.

"We hear from parents every day who are looking to keep their kids as safe as possible by putting them in a school —whether charter or neighborhood school— that looks at all security options,” Carno said. “I'd encourage any school executive to make sure to hear from parents on both sides of this issue, and offer choices that meet those parents' needs within your district."

Colorado’s last fatal school shooting was at a charter school in Douglas County in May.

STEM School Highlands Ranch had an armed private security guard but did not have an assigned school resource officer from the Douglas County Sheriff’s Office.

Several DougCo schools, including STEM School Highlands Ranch, have added SROs for the coming school year.

Court documents indicate that during the May shooting that killed student Kendrick Castillo, the private security guard fired on responding deputies and wounded another student in the process.

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