Like the rest of the nation and world, we are devastated to learn of the loss of 19 children and two teachers to school violence at Robb Elementary in Uvalde, Texas. Each time a tragic attack happens, our research group is asked, “How can we prevent things like this from happening? What should we do when they do happen?” The sad truth is that we know what is needed to prevent violence and support those affected by violence, but we have not consistently put our knowledge into practice. It is time to fully commit to putting what we know works into action. We recommend that federal, state and local efforts invest in: violence prevention, bystander reporting and response, behavioral threat assessment and management, and (when these events do occur) trauma-informed support for children and their families.