SYNOPSISObjective. Homicide and suicide are intentional acts of violence that disproportionately involve firearms. Much more effort has been devoted to the ecological study of homicide; methods that have been developed to better understand and subsequently prevent homicide may be applicable to suicide. The purpose of the present study was to compare the occurrence of firearm homicide and firearm suicide using routine activity theory as a framework for analysis.Methods. Detailed mortality data pertaining to decedents, their neighborhoods, and use of firearms were collected from 1994 to 1998 for the counties containing and surrounding three small to medium-sized U.S. cities. Data from a total of 468 neighborhoods that collectively experienced 1,025 intentional deaths from firearms (396 firearm homicides and 629 firearm suicides) were analyzed.Results. Firearm homicide was consistently associated with outof-home, nighttime activity in neighborhoods where many people were likely to be coming and going. In an opposite-but-equal fashion, firearm suicide was consistently associated with in-home, daytime activity in out-of-the-way neighborhoods.Conclusions. Firearm homicide and firearm suicide were found to be consistently associated with markers of routine activity in all three cities, albeit in an opposite-but-equal manner. Because firearm suicides very often occur as lonely events in lonely neighborhoods, they may go under-noticed relative to firearm homicides. More awareness and additional public health studies of firearm suicide, in tandem with firearm homicide, should be pursued to better identify individuals and neighborhoods that are at greatest risk of experiencing each event.PHOTO: EARL DOTTER