BackgroundDescribe trends in perpetrator characteristics and firearm use in pediatric homicides across the United States.MethodsMultiply-imputed data from the Federal Bureau of Investigation’s 1976–2020 Supplementary Homicide Reports were used to estimate perpetrator characteristics (sex, age, and relationship to victim) and firearm use in pediatric homicides. Descriptive analyses were stratified by victim age group, sex, race, and five-year time periods.ResultsFamily members were the most common perpetrator of infant and toddler (ages 0–4) and child (ages 5–12) homicides, whereas acquaintances accounted for the majority of adolescent (ages 13–19) homicides. Perpetrator characteristics vary across victim sex and race, particularly among adolescents. Despite overall stability, there were changes in perpetrator characteristics from 1976 to 2020. There was a sustained increase in the proportion of homicides committed with a firearm. In 2016–2020, the proportion of firearm-involved homicides was an all-time high for infant and toddler (14.8%), child (53.1%), and adolescent victims (88.5%).ConclusionsPolicy interventions that improve family stability and well-being may be most effective at preventing infant, toddler, and child homicides, whereas programs that target peer and community relationships, as well as policies that focus on firearm access, may be more crucial for preventing adolescent homicides.