The three school shootings that left a principal and six students dead in less than a week have sparked a barrage of pledges from national and state political leaders to tighten campus security. School safety experts urged caution against overreacting to the horrific, but rare, incidents in rural schools in Colorado, Pennsylvania, and Wisconsin. The spate of shootings has thrust school violence into a national spotlight not seen since the 1999 slayings at Columbine High School in Jefferson County, Colorado. Some security measures are suggested in this article. Among them is creating real barriers--the presence of more adults, whether staff members, principals, teachers, or parent volunteers, outside doors, in hallways, and in parking lots--and imagined barriers--measures as simple as signs that tell visitors to report to the front office for a pass, or reminders that the school is in a "gun-free, drug-free zone that tells people there will be more dramatic consequences for certain behaviors"--around schools.