Chapter 2 describes our critical variable, prison population growth, with its trends and patterns. We present data for eighteen countries to document the rapid rise in the prison population and lend proof of its accelerated growth. The chapter analyzes whether the sharp increases resulted from flow (more people incarcerated) or from stock (longer sentences), and evaluates the consequences of each growth pattern. We then characterize the crimes committed by the inmate population (drugs, theft, homicide, etc.), and the type of felonies that were targeted by the criminal justice systems (police, prosecutors and judges). We conclude this chapter by examining the characteristics of inmates locked up in Latin American prisons, their profiles, sociodemographic traits, background, and upbringing.