He is a social scientist researcher who collaborates across disciplines to build evidence for interventions, policies and laws to improve outcomes for adults with serious mental illnesses in the community, and to reduce firearm-related violence and suicide. He is an author of over 250 publications on subjects including the social environmental context of violence in mental illness, implementation of state firearm restrictions related to mental health adjudications, effectiveness of involuntary outpatient commitment, and psychiatric advance directives. Swanson led the research group that published the first empirical evaluations of risk-based, temporary firearm removal laws in Indiana and Connecticut, precursors to Extreme Risk Protection Order laws that were later adopted in many states. He received the 2020 Isaac Ray Award from the American Psychiatric Association and the American Academy of Psychiatry and Law for outstanding contributions to the psychiatric aspects of jurisprudence. He received the 2011 Carl Taube Award from the American Public Health Association for outstanding contributions to mental health services research. Swanson serves on the Executive Steering Committee of the Consortium for Risk-Based Firearm Policy. He previously served as a member of the John D. and Catherine T. MacArthur Foundation Research Network on Mandated Community Treatment and the Methods Core of the Robert Wood Johnson Foundation Public Health Law Research Program. He has delivered numerous endowed lectures including the P. Browning Hoffman Memorial Lecture in Law and Psychiatry at the University of Virginia School of Law and the Raymond W. Waggoner Lecture on Ethics and Values in Medicine at the University of Michigan.