The Secret Service and FBI issued a report on school violence as a result of the mass school shooting in Columbine, CO on April 20, 1999. Mass school shootings have not abated. This month, the Secret Service released Enhancing School Safety Using a Threat Assessment Model: An Operational Guide for Preventing School Violence as a result of mass school shootings at Marjory Stoneman Douglas High School in Parkland, FL and Santa Fe HS in Santa Fe, TX. This report can be accessed at https://www.secretservice.gov/data/protection/ntac/USSS_NTAC_Enhancing_School_Safety_Guide_7.11.18.pdf.
It is in the public domain.