Chapter 2 discussed how the Constitution established a formal criminal justice system in the United States.  
Read the Preamble of the Constitution.
“We the people of the United States, in order to form a more perfect Union, establish Justice, ensure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our posterity, do ordain and establish this Constitution for the United States of America.”