<P> Common law courts usually use an adversarial system, in which two sides present their cases to a neutral judge . In contrast, in civil law systems, criminal proceedings proceed under an inquisitorial system in which an examining magistrate serves two roles by developing the evidence and arguments for one side and then the other during the investigation phase . </P> <P> The examining magistrate then presents the dossier detailing his or her findings to the president of the bench that will adjudicate on the case where it has been decided that a trial shall be conducted . Therefore, the president of the bench's view of the case is not neutral and may be biased while conducting the trial after the reading of the dossier . Unlike the common law proceedings, the president of the bench in the inquisitorial system is not merely an umpire and is entitled to directly interview the witnesses or express comments during the trial, as long as he or she does not express his or her view on the guilt of the accused . </P> <P> The proceeding in the inquisitorial system is essentially by writing . Most of the witnesses would have given evidence in the investigation phase and such evidence will be contained in the dossier under the form of police reports . In the same way, the accused would have already put his or her case at the investigation phase but he or she will be free to change her or his evidence at trial . Whether the accused pleads guilty or not, a trial will be conducted . Unlike the adversarial system, the conviction and sentence to be served (if any) will be released by the trial jury together with the president of the trial bench, following their common deliberation . </P> <P> There are many exceptions in both directions . For example, most proceedings before U.S. federal and state agencies are inquisitorial in nature, at least the initial stages (e.g., a patent examiner, a social security hearing officer, and so on), even though the law to be applied is developed through common law processes . </P>

List and explain the four written sources of american criminal law