Here is a thorough detailed explanation and we in Canada are rushing headlong into the same “almost exclusively system of plea bargaining, negotiated behind closed doors and with no judicial oversight. The outcome is very largely determined by the prosecutor alone.” This is fuelled by mandatory minimum sentences and consecutive minimums such as have been recently introduced here. Don’t be a fool and think you can you can successfully negotiate this yourself or with a free lawyer. You can’t.
Why Innocent People Plead Guilty by Jed S. Rakoff | The New York Review of Books.