The purposes of our criminal Justice system

What are the purposes of our criminal Justice system? in your opinion is one go more important than another?
Can a criminal defendant be prosecuted twice for the same act?
Define each of the following: white collar crime the Sarbanes-Oxley Act, and RICO.
What is the computer fraud and abuse at.
What is a whistleblower? What conflicting ethical duties might a whistleblower encounter.