A Minnesota school district is using bulletproof whiteboards.

The Rocori School District has acquired nearly 200 of the whiteboards, made of a material touted by its manufacturer as stronger than that in police-issue bulletproof vests. The 18-by-20-inch whiteboards can be used by teachers for instruction and used as a shield in an emergency.

The manufacturer, Maryland-based Hardwire LLC, said the whiteboards are already in schools in North Dakota and Maryland, and are being rolled out in Pennsylvania and California. 

Scott Staska, the Rocori superintendent, noted that the boards are a supplement to a broad plan that includes lockdown drills and school resource officers.

In 2003, a 15-year-old boy brought a gun to Rocori High School and fatally shot 14-year-old Seth Bartell and 17-year-old Aaron Rollins. The gunman, who is serving a life sentence, was convinced by a teacher to put the gun down.