From the Executive Summary: "Acts of targeted violence against houses of worship (HoWs) are a real--and potentially growing--problem in the United States and a top priority for the U.S. Department of Homeland Security (DHS). As the Nation's risk advisor, the Cybersecurity and Infrastructure Security Agency (CISA) prepared this guide to help faith-based organizations (FBOs) develop a comprehensive security strategy for adoption to the unique circumstances of every church, mosque, synagogue, temple, and other sites of religious practice across the country. To better understand the nature of the problem, CISA drew on open source research to compile 37 incidents of targeted violence covering the ten-year period from 2009 to 2019. The analysis drawn from these case studies directly informs the guidance presented here and reveals several noteworthy trends."
Cybersecurity and Infrastructure Security Agency: https://www.cisa.gov/