If you're curious about what happens during a preliminary hearing, you've come to the right place.
Also known as a "trial before the trial" or a mini-trial, a preliminary hearing is typically the second step in criminal court proceedings.
It also may be one of the most important steps, as it helps determine whether or not the prosecutors have enough evidence to send a defendant to trial.
If a defendant is not being charged with a crime that requires a grand jury indictment, the first step in criminal proceedings is the arraignment. A quick jaunt in front of a judge, a defendant is expected to make a plea, and then will have a date set for his preliminary hearing.
The preliminary hearing serves as a sort of "check" on the government. Prosecutors must demonstrate that there is sufficient evidence, or probable cause, such that a jury could possibly be convinced that the defendant is guilty.
In some jurisdictions, prosecutors may call a few witnesses--the arresting officer or investigator--and present physical evidence to the presiding judge. Depending on the jurisdiction, non-admissible evidence, such as hearsay, may be considered.
The defense has the option of cross-examining witnesses and challenging evidence, though it's rare that a defendant introduces his own witnesses or testifies himself.
If the judge finds that there is not enough evidence to support a prosecution, then the defendant will be free to go. If there is sufficient evidence, the case is then transferred to trial court, with the defendant returning to prison or remaining out on bail until trial begins.
Keep in mind that this is typically what occurs during a preliminary hearing, but that rules vary by jurisdiction. So if you're expected to attend one in the future, ask your attorney for advice.