Our Grants

Completing the Causal Chain of ERPO Effectiveness: A Parallel Mixed-Method Study


This project will inform process improvement and implementation of extreme risk protection order (ERPO) systems, specifically by understanding the impact of granting vs denying bona fide petitions and by improving states' knowledge about when and how firearms are relinquished and returned.




This project seeks to improve our collective understanding of two under-investigated aspects of ERPO systems: 1) judicial decisionmaking about when to grant or deny a petition, and 2) how to standardize documentation that firearms have been relinquished when an ERPO is granted and returned when it expires.


In Aim 1, we will use a cohort study to evaluate the influence of granting versus denying ERPO petitions on respondents’ risk of criminal justice (CJ) involvement (primary) and death (exploratory), combining data from our internal abstraction of all ERPO petitions in Colorado with CJ outcomes from the Colorado Department of Justice. In Aim 2, we will describe documentation practices for firearm relinquishment and return when ERPOs are granted, using existing ERPO cases as a qualitative cohort. We will use these findings to ground the conduct of a modified Delphi panel of Colorado law enforcement experts to identify possible sources of missing documentation and develop policy strategies to improve documentation.


Findings from these parallel projects will advance the theoretical underpinning of ERPO research (judicial decisionmaking and firearm relinquishment as intermediate endpoints) and practices which improve effectiveness and justice (through improved firearm relinquishment/return).

Investigator Bios

Chris Knoepke is an assistant professor of cardiology at the University of Colorado School of Medicine, where he also serves on the leadership committee for the Firearm Injury Prevention Initiative. His research spans patient centered care in advanced cardiology and firearm injury and suicide prevention, including extreme risk protection orders and voluntary storage programs.

Grant Amount
Award Type
University of Colorado School of Medicine
Chris Knoepke, assistant professor of cardiology at the University of Colorado School of Medicine.
Expected Completion Date
May 2026
Focus Areas