The threat of a school shooting at Middlebury Union Middle School this week exposed a controversial provision of the sweeping gun legislation signed by Gov. Phil Scott in April.

Prosecutors obtained a temporary 14-day “extreme risk protection order” to seize about a dozen firearms from the relative of one of the two students allegedly involved in the plot.

Police say an alert student notified authorities Saturday that she heard the two students discussing the shooting. Middlebury Police Chief Thomas Hanley said investigators quickly learned the details of the plot and considered it credible.

“Very specific date and time, target, how this was going to happen and where the weapons were going to come from,” he said.

Under Vermont’s new gun laws, prosecutors can prohibit a person from possessing a weapon if a court determines it poses “an extreme risk of harm” to the person or others. Extreme risk protection orders have been sought 19 times in 2018, including this week’s incident in Middlebury, according to the Vermont Department of State’s Attorneys and Sheriffs.

Hanley, who describes the confiscated guns as sport firearms and collectibles,” said seizing the guns from the relative, who is not accused of being involved in the alleged plot, “allowed us to at least make things safe for the time, and then we’ll resolve the issues later.”

Whether the relative’s weapons are returned when the 14-day temporary order expires will be up to a judge. Hanley said a hearing is scheduled for next week. Prosecutors could seek a six-month extension under the law.

Hanley said he spoke to the relative about the order and the process by which the weapons will be returned.

“I don’t believe we need to be going into people’s houses that didn’t do anything and take their guns on a whim, but there was clearly immediate access to these and that’s why we had to act,” he said.