Abstract: A security panel system that is adapted to protect innocent bystanders from gunfire in the event of a shooting. The security panel system includes a main body having a first rail, a second rail, a panel, and a locking mechanism. The first rail and the second rail may each be mounted adjacent to a window and movably secure a panel therebetween. The panel is movable between an opened position and a closed position. The locking mechanism is configured to secure the panel in the closed position. It should be appreciated that, while the panel is in the closed position, the shooter may not be able to see or fire through the window due to use of the security panel system.