Fact check: How does the FBI define and track domestic terrorism cases involving right and left extremism?

1. Why the FBI’s Count Matters — “1,700 Investigations” and What That Actually Means

The FBI told the public it was investigating over 1,700 domestic terrorism cases in statements made in mid-September 2025; this number was repeated across reporting about bureau activity and leadership remarks (Sept. 16, 2025). That figure reflects open investigative matters, not convictions or indictments, and includes a range of allegations from plotting to violent acts to threats; the bureau groups cases under the umbrella of domestic violent extremism when the conduct involves violence or the credible threat of violence. The number alone does not map cleanly onto ideological breakdowns because FBI public statements emphasize conduct-based criteria rather than labeling every probe by a simple left/right taxonomy ^[2].

2. How the FBI Defines Domestic Violent Extremism — Violence, Not Belief

The bureau’s operational definition centers on violence or the credible threat of violence committed by individuals or groups without foreign direction; the FBI also stresses that it will not investigate people for constitutionally protected speech, activism, or beliefs (as articulated in recent public explanations). That approach means investigators focus on criminal actions and material support, financial conduits, or operational plotting. The practical effect is that ideology is a contextual element for threat assessment, but the legal and investigative threshold remains violent conduct or facilitation of violence rather than mere affiliation or rhetoric ^{[1] [2]}.

3. What the Data Shows — Right-Wing Violence Dominates Lethality Metrics

Multiple data reviews and reporting in September 2025 show right-wing extremist attacks have been more frequent and deadlier than left-wing attacks, with estimates attributing roughly 75–80% of domestic terrorism deaths since 2001 to right-wing perpetrators. Researchers and reporters cite incident-level datasets and law-enforcement tallies to conclude that lethality and frequency metrics point to a disproportionate share of fatal outcomes linked to right-leaning violent extremism. That empirical pattern influences threat prioritization in practice even though the FBI’s public descriptions remain conduct-focused ^{[1] [3]}.

4. Recent Incidents and Ambiguities — The Pittsburgh Field Office Case

A September 2025 incident where a driver targeted the FBI’s Pittsburgh field office was labeled an “act of terror” by officials; reporting noted the suspect’s former military service and possible mental-health issues, but the account did not clarify ideological drivers or how the event would be coded in ideological tallies. This illustrates a recurring problem: some violent acts lack clear political motive, falling into categories investigators sometimes describe as nihilistic or non-ideological violent extremism. That ambiguity complicates simple left/right counts and underscores the FBI’s emphasis on conduct and immediate threats when opening investigations ^[5].

5. Politics and Policy — A Presidential Memorandum and Its Critics

In late September 2025 President Donald Trump signed a memorandum ordering investigations into “domestic terrorism and organized political violence,” with language and rollout signaling a focus on left-wing actors and funding streams; Attorney General and FBI responses emphasized following money and networks. Civil liberties advocates and some observers criticized the directive as politically motivated and warned it could chill protected activity if applied broadly. The policy move illustrates how administration priorities can reshape public expectations of law enforcement focus, even as the FBI continues to assert legal constraints on investigations ^[4].

6. Divergent Narratives — Law Enforcement Practice vs. Political Framing

Law-enforcement officials frame domestic terrorism work as investigative and evidence-driven, emphasizing violent conduct, organized support, and criminal statutes that permit disruption. Political actors, by contrast, may frame the same issues to highlight particular threats or opponents. The result is two overlapping narratives: one technical and case-focused from the FBI, and one political and selective from policymakers. This divergence fuels debates about resource allocation and civil-liberties safeguards while investigations proceed under statutory and constitutional limits ^{[2] [4]}.

7. What’s Missing from Public Reporting — Data Transparency and Ideological Coding

Public statements and press coverage provide headline counts and case descriptions but often omit methodological detail: how investigators code motive, how many probes convert to charges, and what portion of cases are categorized as right-wing, left-wing, or non-ideological. Researchers advocating for clearer public data stress that transparency on coding rules and outcomes—dates, charges, convictions—would improve public understanding and reduce politicized interpretations. Without consistent, published metrics, comparisons across time and administrations remain challenging ^{[1] [2]}.

8. Bottom Line for Readers — What to Watch Next

Watch for three concrete developments: publication of detailed FBI metrics or DOJ reports clarifying ideological categories and outcomes; follow-up investigations and charges from the 1,700-case portfolio that reveal motive distributions; and administrative or congressional changes that alter investigative priorities. These developments will show whether the bureau’s conduct-based framework produces consistent outcomes across ideologies or whether political directives reshape focus. For now, the public record indicates a conduct-first FBI approach amid data pointing to a higher lethality from right-wing extremism, and evolving political pressures that could influence emphasis ^{[2] [3] [4]}.