Presents data on prisoners under the jurisdiction of federal and state correctional authorities on December 31, 2011, collected from the National Prisoner Statistics series. The report compares changes in the prison population during 2011 to changes from yearend 2000 through yearend 2010. It explores factors leading to the second straight year of decline in the state prison population, as well as continued growth in the federal prison population. Findings cover data on decreasing admissions and releases in state prisons; imprisonment rates for prisoners sentenced to more than one year, by jurisdiction, age, race, Hispanic origin, sex, and offense distributions of prisoners; and the contribution of California’s new Public Safety Realignment policy on the national state prison population.