Describe the working of courts in the United States of America.

Criminal justice in the United States is an adversary system. That is, a prosecuting attorney first presents the state's evidence against a defendant, and that defendant, presumed innocent until proved guilty, then has an opportunity to refute the charges with the assistance of a defense attorney. Contrary to public opinion, more than 90 of convictions in the United States are obtained not in court but through plea bargaining between the prosecuting attorney and the defendant, who is often represented by a defense attorney in the plea-bargaining process. For a plea of guilty, a suspect may receive a more lenient sentence, have certain charges dropped, or have the charge reduced to a less serious offense. Plea bargaining is not legally binding in court, but the judge usually goes along with the arrangement. Plea bargaining is highly controversial. It does save taxpayers considerable expense because court trials are costly. But it may in some cases circumvent due-process protections if an innocent person charged with some serious offense is pressured into pleading guilty to a reduced charge. There are four key positions in a court: the prosecuting attorney, the defense attorney, the judge, and the jury.
Prosecuting attorneys have considerable discretionary authority in choosing whether to seek a conviction for those arrested and how vigorously to prosecute a defendant. Prosecuting attorneys are either elected or appointed to office and are therefore political figures who must periodically seek reelection or reappointment. Therefore, they seek to prosecute most vigorously the cases they perceive the community is most concerned about. Prosecuting attorneys usually focus police departments' attention on which violations will be further processed by the criminal justice system. Defense attorneys are supposed to represent their clients' interest before the criminal justice system. Impoverished individuals are provided, at the state's expense, a court-appointed attorney. The skills and competency of the defense attorney are major factors in determining whether a defendant will be found innocent or guilty if there is a trial. The wealthy not only can retain the best attorneys but also can afford additional resources (such as private investigators) to help prepare a better defense. Sometimes the poor are shortchanged by court-appointed defense attorneys, who tend to be young, inexperienced practitioners, or less competent older lawyers, who resort to this type of practice in order to survive professionally. Because these defense attorneys depend on the good opinion of their legal colleagues (including judges and prosecuting attorneys) to stay in practice, the client's best interest sometimes receives secondary priority. If a defendant is prosecuted for a minor offense, the case is generally presented before a lower-court judge without a jury. For a serious offense, the defendant first receives a preliminary hearing, which is solely for the benefit of the suspect. At the hearing, the prosecutor presents evidence against the suspect, and the judge decides whether that evidence is sufficient to warrant further legal proceedings. If the evidence is insufficient, the suspect is discharged. If the evidence is sufficient, the accused is held over to await a court trial. (Often the held-over cases are then decided by plea bargaining before they go to trial.) A jury is supposed to be a cross section of the community. However, there is a tendency for retired persons, housewives with grown children, and the unemployed-those who are not inconvenienced by the duty-to be overrepresented on juries. Juries use the standard of reasonable doubt to decide if the prosecution has provided enough evidence for conviction. To obtain the conviction of a defendant charged with a crime, all 12 members of the jury must vote guilty. A hung jury occurs when a jury is unable to reach a decision. Because of group pressure, only rarely does a lone juror produce a hung jury. Under the bail system, accused people are allowed to deposit money or credit with the court to obtain a release from jail while awaiting trial. Bail is designed to ensure that the suspect will appear for trial. The amount of bail is set by the court and varies according to the offense and the judge's attitudes toward the suspect. The bail system severely discriminates against the poor. Anyone unable to raise enough money must stay in jail while awaiting trial, which may take several months. Those who cannot post bail have less opportunity to prepare a good defense because they are locked up. Also, their cases are further prejudiced when they do appear in court because they are brought into the courtroom in handcuffs and often without proper grooming. Being locked up before trial is a form of punishment that runs counter to the notion that the suspect is innocent (and should be treated as such) until proved guilty. In some cases, a suspect spends more time in jail awaiting trial than she or he spends in jail if found guilty. After defendants have been found guilty or have pleaded guilty, they return to the courtroom for sentencing. Judges usually have fairly wide discretion in assigning sentences; for example, they can place one murderer on probation, commit another to prison, and in those states where capital punishment is legal, order the execution of a third. Judges base their sentences on such factors as the seriousness of the crime, the motives for the crime, the background of the offender, and their attitudes toward the offender. Judges vary greatly in the extent to which they send convicted offenders to prison, use probation, or assign fines. Concern about disparities in sentences has grown in recent years.