The American justice system has always concerned me, one, because of its focus on punishment as opposed to rehabilitation.  And two, because so much of the process is in other people's hands who have varying interests that diverge from yours.  There are lots of excellent points made in this article by Whitehead.  One of them struck me that seemed to encapsulate for me what the justice system is all about.  It's this:

This phenomenon of innocent people pleading guilty makes a mockery of everything the criminal justice system is supposed to stand for: fairness, equality and justice. As Judge Jed S. Rakoff concludes, "our criminal justice system is almost exclusively a system of plea bargaining, negotiated behind closed doors and with no judicial oversight. The outcome is very largely determined by the prosecutor alone."

It's estimated that between 2 and 8 percent of convicted felons who have agreed to a prosecutor's plea bargain (remember, there are 2.3 million prisoners in America) are in prison for crimes they did not commit.