On February 14, 2018, 19-year-old former student Nikolas Cruz opened fire at Marjory Stoneman Douglas High School in Parkland, Florida. Fourteen students and three staff members were killed, and 17 other people were injured. Cruz was arrested about an hour and 20 minutes after fleeing the scene.

The attack was the deadliest mass shooting at a U.S. high school at the time. Students founded Never Again MSD, an advocacy group that lobbies for gun control. Later that year, Florida enacted new gun restrictions and authorized properly trained teachers to carry firearms, as well as the hiring of more school resource officers.