Meschke, John SWarmbrod, Kelsey Lane2026-02-052026-02-052026-02-052025Warmbrod_washington_0250E_28964.pdfhttps://hdl.handle.net/1773/55303Thesis (Ph.D.)--University of Washington, 2025Biological events pose serious threats to public health, national security, and global stability. Identifyingthe origins of a biological event is critical for effective response and prevention of future events. However, biological attribution remains underdeveloped, lacking a conceptual framework and trusted investigatory processes internationally. This dissertation advances thinking about evidence for biological attribution by examining how diverse stakeholders perceive, interpret, and weigh evidence in the context of biological event investigations and by developing a conceptual framework to guide future efforts. Using a mixed methods approach, this research draws on expert interviews in the scientific, public health, nonproliferation, and policy domains, as well as scenario-based exercises that tested how partici- pants evaluated and prioritized different types of evidence. The findings reveal that across disciplines there are different views on the scope, feasibility, and the role of international organizations for biological attribu- tion. Results highlight tension between scientific complexity and political realities, particularly concerning evidence collection, laboratory analysis, and communication of findings. Scenario exercises demonstrate that while genetic and laboratory data are often considered highly probative, other forms of evidence, such as epidemiological patterns or intelligence reports, are critical in shaping perceived credibility, intent, and actionability. From these insights, a conceptual framework is proposed that integrates technical capabilities, investi- gation strategies, and contextual social and political factors. This framework underscores that attribution is not only a scientific determination, but a multidisciplinary endeavor that requires the convergence of diverse evidence streams, transparent processes, and international confidence building. By systematically exploring the evidentiary, social, and policy dimensions of attribution, this dissertation contributes to filling a critical gap in global biosecurity scholarship. The work offers practical guidance for designing future attribution investigations, informs ongoing debates about deterrence and accountability, and lays the groundwork for developing international norms and frameworks that can enhance preparedness, trust, and resilience in the face of biological threats.application/pdfen-USnonePublic healthInternational relationsMicrobiologyPublic health geneticsThesis