The initial appearance and arraignment are two separate but related court proceedings that occur early on in an criminal case. Your initial appearance and arraignment will be held in front of a magistrate judge in a single proceeding. The magistrate judge is not the judge who will ultimately hear your case. After the initial proceedings your case will be heard by a district court judge. The initial appearance is the first court appearance during which the judge will inform you of the charges against you and the maximum and minimum penalties are for those charges. You will be asked if you understand the charges. You will be informed of your rights, including the right to counsel. You will be asked to fill out a financial declaration which the court will use to determine whether you are eligible for a public defender. The magistrate judge will schedule a date, usually in two weeks, for the government to provide discovery in your case.
An arraignment is technically the entry of a plea. Because a “not guilty” plea is automatically entered for all defendants at the initial hearing, it is customary to waive formal arraignment.
If you are charged by Complaint or Information, you are also entitled to a preliminary hearing to determine whether there is probable cause for the case to proceed. This is because a case charged by Complaint or Information has not been before a grand jury to determine probable cause. During a preliminary hearing, the magistrate judge listens to evidence to presented by the prosecution, such as witness testimony or physical evidence, and decides if there is sufficient evidence for the case to move forward against you. The standard of proof is lower than that of trial, and the prosecution needs to just establish that there is enough evidence to justify holding you to await trial, and not to determine whether the evidence is enough to convict you. It is not uncommon to waive this procedure too. If you have already been charged by Indictment, you are not entitled to a preliminary hearing because the grand jury has already found probable cause to charge you.
Pretrial release or detention may be considered at the initial hearing. If the government asks for a 72 hour delay, that will be granted and your pretrial release/detention hearing will be heard in a few days. Your lawyer may also want to delay the pretrial release/detention hearing if she or he needs additional time to properly prepare.