Institution of the prosecution.
Criminal cases start with the filing of a complaint alleging the defendant has committed an offense.
A complaint must state the essential elements of the offense and be sworn to by the officer having first hand knowledge of the offense.
The offense may be either a felony or a misdemeanor. Upon filing the complaint with the local court, the officer may request that a warrant issue for the person's arrest, or that summons issue ordering the person to appear in court for an initial appearance.
If a complaint is filed contemporaneously with an arrest, the person is held pending the initial hearing (assuming they do not bond out under a bond schedule).
Whereas a complaint can serve as the basis for an entire misdemeanor prosecution, it is of limited purpose in felony cases. The defendant is not required to enter a plea to a felony complaint. Instead, the defendant appears at the initial hearing to be informed of the charges and the right to counsel and to be admitted to bail. The matter is then set for a preliminary hearing to determine if the defendant should be bound over to the felony court. In many instances, an indictment is issued prior to the preliminary hearing, making the hearing unnecessary.
In felony cases, evidence may also be presented directly to a grand jury that can issue a direct indictment upon concurrence of seven or more of the jurors. If this occurs, the court either issues a summons for the person to appear at an arraignment, or the prosecution may obtain a warrant on the indictment ordered law enforcement to locate the person and arrest them pursuant to the indictment. Upon arrest, the person is held for arraignment.