The U.S. Department of Homeland Security (DHS), the FBI, and the National Counterterrorism Center (NCTC) have published a “slicksheet” on homegrown violent extremists (HVEs), providing an overview of the threat and listing a series of behaviors and activities that could signal mobilization to violence by these individuals. In the document, DHS, the FBI, and the NCTC observe that “HVEs remain the primary international-linked terrorist threat to the Homeland.” Being familiar with the behaviors and activities of HVEs is extremely important for addressing this threat because, as noted in the slicksheet, bystanders witnessed or became aware of an HVE’s violent extremist views or activities nearly 80 percent of the time, providing an invaluable opportunity to intervene and report suspicious activity to authorities. For a full list of HVE mobilization indicators, the slicksheet references the Homegrown Violent Extremist Mobilization Indicators booklet, which was published in January of this year and is available at WaterISAC.