1. Kettl DF: System under Stress: The Challenge to 21st Century Governance. 3rd ed. Washington DC: CQ Press, 2007.
2. US Department of Homeland Security: Fiscal year 2021: Budget in brief. 2021. Available at https://www.dhs.gov/publication/fy-2021-budget-brief. Accessed July 1, 2022.
3. Federal Bureau of Investigations: Active shooter resources. 2021. Available at https://www.fbi.gov/about/partnerships/office-ofpartner-engagement/active-shooter-resources. Accessed October 29, 2021.
4. US Department of Homeland Security: Active shooter preparedness. Cybersecurity & infrastructure security agency. 2021. Available at https://cisa.gov/active-shooter-preparedness. Accessed October 29, 2021.
5. ALERRT: Advanced law enforcement rapid response training: About ALERRT. 2021. Available at https://alerrt.org/about. Accessed October 29, 2021.