ORIGINAL CONTRIBUTION Open Access Extreme risk protection orders in King County, Washington: the epidemiology of dangerous behaviors and an intervention response Shannon Frattaroli 1,2* , Elise Omaki 2 , Amy Molocznik 2 , Adelyn Allchin 3 , Renee Hopkins 4 , Sandra Shanahan 5 and Anne Levinson 6 Abstract Background: Extreme Risk Protection Order (ERPO) laws are a promising gun violence prevention strategy. ERPO laws allow specific categories of people (law enforcement in all states, family in most) to petition a court to request that an individual be temporarily prohibited from purchasing and possessing firearms because that individual is behaving dangerously and at risk of violence, either to themselves or others. In 2017 Washington State’s ERPO law took effect. King County developed a comprehensive approach to implementing the ERPO law. The early experience of King County offers important insight into how early adopters of these laws are incorporating EPROs into their approach to gun violence prevention. Methods: We systematically reviewed, abstracted and coded data from every ERPO petition filed in King County in 2017 and 2018, and all ERPO court records associated with those petitions. We conducted descriptive analyses of the coded data. Results: Seventy-five ERPO petitions were filed in King County during the study period. Judges granted a temporary ERPO in all 75 cases; 65 (87%) of these cases resulted in a one-year ERPO. Law enforcement initiated 73 (97%) of these petitions, and family members filed the remaining two. The 75 petitions filed described respondents’ risk as to “themselves only” in 30 cases (40%), to “others only” in 20 cases (27%) and “to themselves and others” in 25 cases (33%). Five cases where the threat was to “others only” met a definition of mass shooting threat. For 95% of the temporary ERPOs issued, the courts’ reasoning for issuing ERPOs included either current violence or brandishing a firearm. Court records for the 75 cases detail firearms removed and/or include receipts for removed firearms in 61 cases (81%) either as part of ERPO precipitating events (n = 13, 17%) or in conjunction with ERPO service (n = 48, 64%). (Continued on next page) © The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. * Correspondence: Sfratta1@jhu.edu 1 The Johns Hopkins Bloomberg School of Public Health, Center for Gun Policy and Research, 624 North Broadway, Baltimore, MD 21205, USA 2 The Johns Hopkins Bloomberg School of Public Health, Department of Health Policy and Management, 624 North Broadway, Baltimore, MD 21205, USA Full list of author information is available at the end of the article Frattaroli et al. Injury Epidemiology (2020) 7:44 https://doi.org/10.1186/s40621-020-00270-1