Research on spatial injury patterns is limited by a lack of precise injury occurrence location data. Using linked hospital and death records, we examined residence and injury locations for firearm assaults and homicides in or among residents of King County, Washington, USA from 1 January 2010 to 31 December 2014. In total, 670 injuries were identified, 586 with geocoded residence and injury locations. Three-quarters of injuries occurred outside the census tract where the victim resided. Median distance between locations was 3.9 miles, with victims 18–34 having the greatest distances between residence and injury location. 40 of 398 tracts had a ratio of injury incidents to injured residents of >1. Routine collection of injury location data and homelessness status could decrease misclassification and bias. Researchers should consider whether residential address is an appropriate proxy for injury location, based on data quality and their specific research question.