A preliminary hearing is like a mini-trial where prosecutors put witnesses and/or evidence against a felony defendant.
Unlike a trial where the legal standard is beyond a reasonable doubt, in a preliminary hearing there is a lesser legal standard of probable cause for the charges.
During a preliminary hearing and after hearing the evidence, a judge, not a jury, decides whether there is enough evidence or probable cause to hold a defendant for trial.
Defense attorneys during preliminary hearings use the proceedings to find out how much and what kind of evidence prosecutors have against their clients.
If the judge finds there is no probable cause to believe an offense has been committed, the judge must dismiss the criminal complaint and discharge the defendant.
But the prosecution can turn around and file charges again against the defendant for the same offense.
About 95 percent of the preliminary hearings that I attended during my 18 years of covering the courts as a newspaper reporter resulted in findings that there was probable cause to hold defendants for trials.