
The Nationwide Suspicious Activity Reporting (SAR) Initiative (NSI), which facilitates the process of reporting and investigating suspicious behaviors potentially indicative of terrorist activity, has been identified as a tool that can be used to concurrently prevent both terrorism and targeted violence. The NSI captures preoperational behavior in 16 discrete SAR indicators which have been evaluated in the context of terrorism. Yet, these indicators lack systematic evidence to substantiate the application to non-ideological targeted violence, despite a growing body of research on preoperational behavior preceding acts of mass and school violence. This study conducts a scoping review of empirical research on SAR-related behaviors, terrorism, and non-ideological targeted violence. Findings from this review indicate the empirical evidence on SARs is preliminary but growing, and points to key gaps in data, methodology, and focus of existing research. The purpose of this review is to contextualize the current evidence base informing the NSI program and guide future research contributing to this area of research.

