=Trial of Criminal Cases.=--Criminal actions, unlike civil actions, are brought, not by the injured party, but by the state whose peace and dignity have been violated by the act complained of. The officer who brings the action in the name of the state is called the _prosecuting attorney_, the _district attorney_, or the _state's attorney_. He conducts preliminary investigations into crimes and presents cases to the grand jury for indictment. If the grand jury returns the indictment, that is, decides that the accused shall be held for trial, the prosecuting officer takes charge of the case and conducts it for the state. _The Arrest._--Usually the first step in the trial of a person charged with crime is to cause his arrest. The person injured, or any one else who may have knowledge of the crime, appears before a magistrate and makes a complaint setting forth the facts in regard to the crime. If the magistrate is satisfied as to the truth of the complaint, he issues a warrant commanding the sheriff or some other police officer to arrest the accused. The warrant must particularly describe the offense, the place where committed, and the circumstances under which it was committed, and must give the name of the person to be arrested. But in some cases an arrest may be made without a warrant, as when an offender is seen committing a crime or when an officer has good reason to believe that the person who is charged with committing a crime is the guilty person. In practice, policemen frequently arrest on mere suspicion, and if they do so in good faith they will rarely be held liable for damages. Any private individual, as well as an officer, may arrest without warrant a person whom he sees committing a crime. He may also arrest a person whom he suspects of having committed a capital crime, although without personal knowledge of his guilt.[18] [18] Baldwin, The American Judiciary, p. 227. _Commitment._--When arrested the accused is brought before a justice of the peace and examined. If the justice of the peace, after such examination, believes that the accused should be held for trial, he is committed to jail. If the offense is a minor one it can be tried by the justice of the peace. If it is a more serious crime the justice of the peace can hold the offender to await the action of the grand jury. _Habeas Corpus Proceedings._--If at any time it is alleged that a person is unlawfully deprived of his liberty, a judge may issue a writ of habeas corpus and inquire into the case. In this way an accused person may be set free if there is no sufficient reason for holding him.