Just because the police arrest someone and the government charges him or her with a crime doesn't mean that the accused will have to stand trial. Either a judge or a panel of citizens decides if there is enough evidence to have a trial. The federal government and half of the states provide for a panel of citizens, known as a grand jury, to decide if there is probable cause for believing that the accused committed the crime he or she is charged with. Grand juries are often larger than trial juries, consisting of 12 to 23 members. If a majority of the grand jurors finds there is probable cause to support the criminal charge, the grand jury approves an indictment.
The future abolition of grand juries
It is a safe bet that, sometime in the near or distant future, grand juries will be abolished because they are the antithesis of due process. Unlike trials, grand jury proceedings are private and secret, and hearsay evidence (evidence that is not first‐hand) is admissible (it is inadmissible in criminal trials). The defendant has no right to be present at grand jury proceedings and no right to cross‐examine witnesses. The concept of “innocent until proven guilty” doesn't apply. Only the prosecution presents evidence in these ex parte (one‐party) proceedings, and it doesn't have to prove that the accused committed the crime.
Historically, the grand jury was created to serve as a shield to protect citizens from unfounded charges made by overzealous and/or politically motivated prosecutors. Critics charge, however, that the grand jury has become a tool for the very prosecutorial misconduct that it was intended to prevent. Procedural rules of the grand jury favor the prosecution. The exclusionary rule doesn't apply. Because the grand jury gets only the prosecution's version of the evidence, it is likely to find probable cause that the suspect committed the crime charged. Grand juries indict defendants at a rate of 99.9 percent, suggesting that they are rubber stamps for the prosecutor.
The preliminary hearing
In contrast to a grand jury hearing, a preliminary hearing takes place in public, with the defendant and the attorneys for both sides present. At this stage, a lower court judge reviews the prosecution's evidence to see if there is enough evidence to support the criminal charges. The standard for testing the evidence is probable cause.
Because both the prosecution and the defense are represented in a preliminary hearing, it is considered an adversary proceeding. The defendant has counsel who challenges the prosecution's evidence and introduces evidence on behalf of the accused. If the judge finds probable cause, the judge sends the case forward to the trial court.
If a case survives the screening of the preliminary hearing or the grand jury review, it goes to a trial court. At the arraignment, the judge informs the defendant of the charge and asks for a plea. The defendant pleads not guilty, guilty, or nolo contendere (no contest). A no‐contest plea has the same effect as a guilty plea, except there is no formal admission of guilt. If the defendant pleads not guilty, the judge sets the case for trial.
Prior to the trial, both the prosecution and the defense can make motions. A motion for discovery is a request for the prosecution to make available to the defense evidence the prosecution plans to introduce at the trial. The prosecutor is also obligated to turn over any exculpatory evidence—that is, evidence that might establish the defendant's innocence. A motion to suppress is a request to bar certain evidence (for example, a forced confession) that either the prosecution or defense intends to use during the trial.