Maximizing the barrier to entry is one of the best methods for combating the threat of an active shooter on school campuses. Because glass windows and doors are the weakest structural elements of any building, reinforcing them with window film is relatively easy and cost-effective. Film keeps broken glass in the frame so intruders can't crawl through or unlock a door, and delays their ability to enter the school. Shattered glass doesn't injure students. Tinted film allows students to see out and keeps intruders from looking in.