From School Library Journal:

The Alameda County Juvenile Justice Center houses approximately 250 inner-city youth, the majority of whom are African American and Latino, with a small percentage of Asians, Caucasians, and Native Americans. There are about 200 boys and 50 girls, ranging in age from 9 to 18 with the bulk of kids on the older end of the scale.

The average reading level is fifth grade. The average stay is two to four weeks, and many kids are repeat visitors. Many of them have been abused or neglected and have been removed from foster homes and sent to group homes. Often, they run away or commit crimes, such as stealing, and end up coming back to the Hall, as the juvenile facility is called. Sometimes these kids also end up being incarcerated because of outstanding warrants and some of them can be detained for a long time. It’s not a great system, but it’s a great thing that we can at least provide them with books.

Read more : “Inside the Juvenile Detention Center“