A felony criminal case in Idaho state court may begin either by indictment or by the filing of an information. If the state opts for information (think of this as a formal complaint but no grand jury proceeding), a preliminary hearing will be held to determine if there is probable cause to believe that the defendant has committed a felony crime. Now this is not the situation with misdemeanors – a preliminary hearing only applies to felony cases.
Here’s the way this works – suppose that you are suspected of grand theft of $20,000 from a neighbor. The state prosecutor might go to a grand jury – the "secret" body that can "indict" a person if it finds there is probable cause, or the state can simply charge the offense and go to a preliminary hearing. Both the grand jury and the Magistrate at a preliminary hearing are charged to determine whether there is probable cause to believe that the crime has occurred and the charged person is liable. The test for probable cause is whether it is more likely than not that the person committed the charged offense. "More likely than not" is not proof beyond a reasonable doubt – it is just proof that makes it more probable than not the crime occurred.
The alternative way to get this $20,000 theft before an Idaho district court is to use the preliminary hearing process. Instead of a grand jury, the probable cause determination is made in an open, public hearing before a magistrate judge. The person facing the charge will be present, can have a lawyer to cross-examine the witnesses and best of all, everyone can evaluate the witnesses.
But should you waive your right to the probable cause hearing? This question arises because the state usually conditions any plea agreement on a waiver of the preliminary hearing. They frequently say something like: "Look, if you agree to waive the prelim, we will agree to recommend probation on a plea to the theft." In truth, the state would rather not have to go through the process of calling witnesses and having the hearing.
If you want to preserve the plea offer, you may decide to waive the preliminary hearing and let the case go to the district court. If you have already waived that other important right – to not say anything incriminating – and confessed to the theft, proving probable cause could be limited to your own confession. If you waive the preliminary you are usually only giving up the right to have the magistrate determine probable cause, but the burden of proof for probable cause is, as I said above, not proof beyond a reasonable doubt but proof by a preponderance.
Talk to your lawyer about this as you head to a preliminary hearing. Have a plan – often that plan is intended to limit you punishment and waiving the preliminary hearing may not have any real effect in your case. There was a time when magistrates gave a serious look at the probable cause determination, but it seems to me that the lower burden of proof almost always insures a finding that binds over the case to the district court, so you may not be giving up much when the hearing is waived. On the other hand – if you are going to trial you may gain valuable information about the state’s case by forcing them to put on their witnesses at a preliminary hearing.