Extremism in policing: researching a hidden institutional threat

Purpose Extremism within law enforcement represents a growing threat to democratic governance, civil rights and the organizational legitimacy, yet systematic empirical research remains limited. This research examines why extremism in law enforcement is difficult to study and proposes strategies for developing credible baseline estimates of its prevalence. Design/methodology/approach Drawing on research from both policing and military institutions across democratic contexts, we identify structural and methodological barriers to studying extremism in decentralized law enforcement systems. We adapt established approaches from military extremism research to propose a multi-method framework that integrates archival analysis, disciplinary records, media investigations and anonymous survey data. Findings We argue that decentralization, professional gatekeeping and definitional ambiguity obscure its detection. Reliance on official records alone is insufficient to estimate prevalence. A combined multi-method strategy offers a more robust pathway for identifying patterns of extremist ideology while accounting for institutional barriers to detection. Originality/value This article reconceptualizes extremism in policing as an institutional vulnerability rather than isolated misconduct and bridges previous literature on military extremism and policing research. There is a need for credible baseline estimates and we are proposing a concrete research framework. By doing this, we advance both theoretical clarity and practical tools for studying extremism infiltration within democratic security institutions.