This webpage on schoolsafety.gov provides links to several resources related to threat assessment and reporting that can help "identify and address threatening or concerning behaviors before they lead to violence." From the webpage: "Reporting on a variety of concerning student behaviors and other suspicious activities provides authorities and school personnel with the information they need to stop violence before it occurs. A 2008 study showed that, prior to an act of violence, most attackers behaved in a way that made others concerned, and other people knew about the attacker's plan. Having a threat assessment program, or a multidisciplinary group process, to evaluate these reports can significantly reduce violence, including mass casualty attacks. Schools should establish a reporting system that is continually monitored and allows anonymous reporting. Districts and schools should establish multidisciplinary teams and threat assessment programs to assess each report and respond to threats of violence and other concerning behavior."
School Safety.gov: https://www.schoolsafety.gov/