Breaking the silence: Bystander reporting to law enforcement disrupts individuals moving toward targeted violence

In an answer to increasing calls to prevent mass violence, law enforcement has partnered with multidisciplinary community shareholders to develop threat assessment teams that actively work together to mitigate potential mass attacks. As bystanders report concerning behavior to law enforcement, these teams work to identify, assess, and manage these concerns in a manner aimed to mitigate the potential for violence and provide necessary support to individuals whose behavior caused concern. To date, there is limited empirical research regarding specific interventions that disrupt individuals moving toward targeted violence.

A key focus was to determine if disrupted persons of concern (POC) for violence were more likely to have been reported to law enforcement by bystanders than the active shooter group. In addition, we sought to determine whether the proposed mitigating factor of being "on the radar" moderates targeted violence.

The present study examined a matched sample of 72 active shooters (AS) and 74 POC who had been assessed by a threat assessment team. The sample was coded using the North Carolina Behavioral Threat Assessment Investigation-25 structured professional judgment tool.

The odds of an individual being classified in the POC group were 33.37 times higher if a law enforcement agency had been previously alerted to concerns about them. Monitoring by agencies other than law enforcement was not significantly predicative of group membership. Concerned others with a much wider range of relationships had made reports to law enforcement about POC, resulting in markedly higher rates of bystander reporting than for AS (M = 4.91 alerts to law enforcement for POC vs. M = 0.48 reports for AS; p = .032).

These findings emphasize the importance of ongoing law enforcement participation in threat assessment teams and the necessity of bystander education in specific behaviors to watch for and report. (PsycInfo Database Record (c) 2025 APA, all rights reserved).