The most recent comprehensive demographic study of the California prison system was completed in 2013. According to this state prison census, there were 134,160 inmates in California correctional facilities that year. Of these, 39,451 prisoners were African American, representing 29.4% of all inmates. A less extensive 2016 survey shows similar numbers, indicating that these figures are more or less stable. 55,421 prisoners were Latino in 2013. This represents 41.3% of California inmates. Latinos are the largest racial group by far in the California prison system. 23% of inmates are white, and 6.3% belong to other racial groups. Numbers relating to the probation and parole systems are less easy to come by, but it is likely that similar percentages exist.

One glaring issue is that African Americans and Latinos are overrepresented in the state's prison system. According to census estimates from 2015, California's total population is 39% Latino and 6.5% African American. This shows that, for African Americans in particular, a disproportionate amount of the population is in the prison system.

According to statistics shown in the two links below, the percentage of California’s adult prisoners who are Hispanic or Latino and who have been sentenced on felony charges is 42%.  This means that Hispanics are somewhat overrepresented in the prison population relative to their percentage of the state’s adult population as a whole.  Hispanics make up 33% of the state’s adult population. 

African Americans are also overrepresented in the California prison system.  African American prisoners constitute 26% of the population in state prisons.  This is true even though African Americans only make up 6% of the state’s adult population.  The fact that so many African Americans are incarcerated is one of the factors that make many people worry about the impact of “mass incarceration” on the African American community.

The rest of California prison population is made up of whites (28%) and other races (4%).