Education and training are stressed as the most effective means to prevent school violence. Six early warning signs of violent prone students are presented and explored in detail. The six warning signs include: fascination with weapons; self-exposure to violent media; suicidality; mental and physical rehearsal; and threats and disturbing comments. Research into post-incident analysis demonstrates that early warning signs are consistently present before school shootings. Threats should be recognized, reported, and addressed promptly to prevent school violence. Through education and training students and teachers can be empowered to detect the early warning signs, address them, and prevent deadly violence in schools. Education and training is preferable to high tech security measures including metal detectors.