I just finished reading the short sequel to THE LEMONADE WAR, which is THE LEMONADE CRIME by Jacqueline Davies. The story speaks to fourth grade students about how the justice system works. Each chapter began with a definition of a word connecting to a crime. 

For example:
ACCUSED: (A person who has been charged with a crime or who is on trial fro a crime).
I can't wait to share this book-talk with the fourth grade students.