Several studies have found that schools that have used threat assessment programs see as few as 0.5 to 3.5 percent of students carry out a threat of violence or attempt to, with none of the threats that were carried out being serious threats to kill, shoot, or seriously injure someone.

Cornell D., et al. “Student Threat Assessment as a Standard School Safety Practice: Results from a Statewide Implementation Study”. School Psychology Quarterly. (2018). https://doi.org/10.1037/spq0000220; Burnette A., et al., “School Threat Assessment versus Suicide Assessment: Statewide Prevalence and Case Characteristics”. Psychology in the Schools. (2019). https://doi.org/10.1002/pits.22194; Burnette A., Datta P., and Cornell D., “The Distinction between Transient and Substantive Student Threats”. Journal of Threat Assessment and Management. (2018). https://doi.org/10.1037/tam0000092.