School shootings and other attacks that indiscriminately target victims pose special challenges for explanation. Their rarity, enigmatic psychology, and media appeal make it difficult to define the phenomena-to-be-explained in ways well suited for discovering persuasive etiological processes. Here theory in criminology has an especially valuable role to play. Working from general principles for interactively defining the problem to be explained and for developing explanatory hypotheses, I offer an explanation of ‘intimate massacres’ as the upshot of three contingencies: the pursuit of a point of no return; a project of destroying one’s personification in a given place; and a compelling desire to transform emotional chaos into a crystallized line of irresistible action. Once the motivation in the foreground of intimate massacres is understood, the relationship of these events to biographical and social ecological background factors will be comprehended in ways that contest the associations often suggested by folk sociology.