Most criminal cases in the United States do not result in trials. Instead, prosecutors and defendants, usually through their defense attorneys, agree to a settlement prior to trial which resolves the case. This agreement will generally allow a defendant to change his plea from not guilty to guilty or no contest in return for a lesser sentence than he or she might have faced had the matter been tried and a conviction resulted. Although the practice of plea bargaining is controversial among some, it provides significant advantages for all sides. First, it provides certainty to the defendant who knows exactly how the case will be resolved and how much time he or she will face, usually less than what might happen at trial. Second, it provides similar certainty for the prosecution, and additionally avoids what is often traumatic testimony for crime victims at trial, where they might need not only to face offenders and their attorneys, but would also have to confront defense attempts to discredit them. Finally, the plea bargaining process allows the system to avoid the time and expense of trials. Currently, approximately 85-95% of criminal cases result in negotiated settlements, depending on the type of case. The court system would be unable to accommodate trials for all of these matters without a massive increase in resources.
For the most comprehensive study of the disposition of defendants within the criminal justice system, see the latest report on felony arrest processing in large American counties, produced by the federal Bureau of Justice Statistics. This study is one that is repeated periodically by this agency and reflects processing trends in state justice systems.