But Craig said a number of school board members and administrators voiced support for the bill.
"There are plenty of school districts that let us know that they've wanted this, and they've wanted this kind of provision for quite some time," he said.
On Monday, the South Dakota House voted 40-19 to accept the Senate version of the bill, which added a requirement that a school district must decide in a public meeting whether to arm teachers and others. Another Senate amendment allowed school district residents to push a school board's decision to a public vote.
Craig said he couldn't say how a typical district would implement a sentinel policy, as those decisions will be made locally.
"They get to work out the details in the days ahead," he said. "They've just kind of been waiting and watching to see if this even would pass."
Monson said school districts are going to want to know how the bill's passage will affect them.
"Our biggest challenge right now will be answering all the questions that school boards and administrators are going to have about liability issues and all the other pieces that haven't been put in place yet," Monson said.
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