In a criminal case, the government generally brings charges in one of two ways: either by accusing a suspect directly in a "bill of information" or other similar document, or by bringing evidence before a grand jury to allow that body to determine whether the case should proceed. If there is, then the defendant is indicted. In the federal system, a case must be brought before a grand jury for indictment if it is to proceed; some states, however, do not require indictment.
Once charges have been brought, the case is then brought before a petit jury, or is tried by a judge if the defense requests it. The jury is selected from a pool by the prosecution and defense.
The burden of proof is on the prosecution in a criminal trial, which must prove beyond a reasonable doubt that the defendant is guilty of the crime charged. The prosecution presents its case first, and may call witnesses and present other evidence against the defendant. After the prosecution rests, the defense may move to dismiss the case if there is insufficient evidence, or present its case and call witnesses. All witnesses may be cross-examined by the opposing side. The defendant is not required to testify under the Fifth Amendment to the United States Constitution, but must answer the prosecution's questions if he or she takes the stand. After both sides have presented their cases and made closing arguments, the judge gives the jury legal instructions and they adjourn to deliberate in private. The jury must unanimously agree on a verdict of guilty or not guilty.
If a defendant is found guilty, sentencing follows, often at a separate hearing after the prosecution, defense, and court have developed information based on which the judge will craft a sentence. In capital cases, a separate "penalty phase" occurs, in which the jury determines whether to recommend that the death penalty should be imposed. As with the guilt phase, the burden is on the prosecution to prove its case, and the defendant is entitled to take the stand in his or her own defense, and may call witnesses and present evidence.
After sentencing, the defendant may appeal the ruling to a higher court. American appellate courts do not retry the case; they only examine the record of the proceedings in the lower court to determine if errors were made that require a new trial, re-sentencing, or a complete discharge of the defendant, as is mandated by the circumstances. The prosecution may not appeal after an acquittal, although it may appeal under limited circumstances before verdict is rendered, and may also appeal from the sentence itself.