Whether probable cause is established in a criminal complaint, or through a formal grand jury indictment, an accused is often arrested after the issuance of a formal arrest warrant.  The exception to this practice exists in exigent circumstances where a person commits a crime in the presence of law enforcement, or it would be dangerous to wait for a more formal process before arresting the accused.

After a person is arrested, a pretrial services or probation officer of the court immediately interviews the defendant and conducts an investigation of the defendant's background. The information obtained by the pretrial services or probation office will be used to help a judge decide whether to release the defendant into the community before trial, and whether to impose conditions of release.

Even before a formal arraignment, a court commissioner or other authorized official may release an accused on his own recognizance or release the accused upon the posting of bail money.  Ultimately, the decision on whether to place a defendant in pretrial detention or to release the accused on certain conditions is made by a judge upon the arraignment of the accused in court.