The Florida high school where 17 people died after being shot in February is requiring its students to wear clear backpacks in hopes that the move will prevent further gun violence.

Broward County Public Schools Superintendent Robert W. Runcie announced Wednesday in a letter to parents of Marjory Stoneman Douglas High School students that all pupils will only be allowed to wear clear backpacks to school after next week’s spring break.

Runcie added that the district would provide those backpacks at no cost to students who cannot afford them once the rule goes into effect.

The move by the district comes as the school attempts to introduce other security measures—including possible airport-style metal detectors at the entrance and identification badges for students, faculty, and staff members—to prevent another shooting such as what took place on February 14.

The school already implemented heightened security measures Thursday ahead of the rules taking effect. Florida Gov. Rick Scott ordered eight highway patrol officers to provide security for the school after authorities arrested Nikolas Cruz’s brother, Zachary, Monday for allegedly trespassing on school grounds after he was told to stay away from the campus.

The Broward County Sheriff’s Office also announced it arrested three high school students Tuesday—one for allegedly making threats via Snapchat and two for allegedly carrying knives—prompting Scott to offer assistance to Broward County Sheriff Scott Israel and Runcie in the form of state patrol officers.

“Parents, students, and teachers have recently endured one of the worst tragedies in Florida history,” Gov. Scott said. “They must be assured that every necessary step is being taken to increase safety and ensure no unauthorized people are allowed on campus.”

The patrol officers, along with Broward County deputies, will be on guard at every campus entry point and will remain there indefinitely.

The school had been patrolled by one armed deputy and several unarmed guards before the massacre.

Some students decried the “clear backpack” rule and other security measures as inefficient, saying the proposed measures will not stop gun violence.

One student tweeted that the backpack rule would only make the school environment more like a prison.

“s/o to America for making my school seem like jail now because legislators don’t have common sense gun reform on their agendas,” the student, a senior, tweeted.

Other students expressed concerns about the school district invading students’ privacy and spending money to give students the backpacks.

“I know having clear backpacks will help with security, but now all my privacy will be gone. I wish it didn’t come to this,” another Marjory Stoneman Douglas student tweeted.

“Spending money on giving us clear backpacks is a joke,” another student wrote on Twitter.