in criminal law, a hearing to determine if a person charged with a felony (a serious crime punishable by a term in the state prison) should be tried for the crime charged, based on whether there is some substantial evidence that he/she committed the crime.
A preliminary hearing is held in the lowest local court (municipal or police court), but only if the prosecutor has filed the charge without asking the Grand Jury for an indictment for the alleged crime. Such a hearing must be held within a few days after arraignment (presentation in court of the charges and the defendant's right to plead guilty or not guilty).
Since neither side wants to reveal its trial strategy, the prosecution normally presents only enough evidence and testimony to show the probability of guilt, and defendants often put on no evidence at all at the preliminary hearing, unless there is a strong chance of getting the charges dismissed. If the judge finds sufficient evidence to try the defendant, the case is sent to the appropriate court (variously called superior, county, district, common pleas) for trial.
If there is no such convincing evidence, the judge will dismiss the charges.
From the defense perspective, the preliminary hearing is one of the most important steps in the criminal justice process since you get an opportunity to hear the evidence against you, evaluate witnesses and effectively map out a strategy for your defense.
Pittsburgh Criminal Defense Attorney Frank Walker