Drawing upon both ethnographic research and genealogical analysis, this book represents the first in-depth scientific analysis of criminal offenders’ electronic monitoring (EM) in Latin America’s largest country. It focuses on three empirical axes: 1) the implementation of EM policies against the backdrop of Brazil’s collapsing carceral system; 2) the discourses and rationalities which undergird the deployment of EM; and 3) the effects of EM upon convicts moving back and forth between penal institutions and urban spaces governed by armed militias, criminal gangs, and abusive police forces. The book is ideal for researchers and practitioners concerned with the fields of criminal justice and public security all over the world.