A true story of violence, punishment, and a transformative moment in Guatemalan history that “deftly ranges across Italian iconography, Maya cosmovision, casta paintings, Enlightenment urbanism, conceptions of death, masculinity, gender violence, crime and punishment, and the growth of the state.” (Laura Matthew, Hispanic American Historical Review) On the morning of July 1, 1800, a surveyor and mapmaker named Cayetano Díaz opened the window of his study in Guatemala City to find a horrific sight: a pair of severed breasts. Offering a meticulously researched and evocative account of the quest to find the perpetrator and understand the motives behind such a brutal act, The Woman on the Windowsill pinpoints the last decade of the eighteenth-century as a watershed moment in Guatemalan history, when the nature of justice changed dramatically. Sylvia Sellers‑García reveals how this bizarre and macabre event came with an increased attention to crime that resulted in more forceful policing and reflected important policy decisions not only in Guatemala but throughout the Spanish Empire. This engaging true crime story serves as a backdrop for the broader consideration of the forces shaping Guatemala City at the brink of the modern era.