“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.” U.S. Constitution, Fourth Amendment.
The United States Constitution protects defendants across the criminal justice system through the enumerated rights listed under the Bill of Rights. One of these rights, found in the Fourth Amendment, is the right to have all warrants issued upon them, including arrest warrants, be based on probable cause. This right is protected in part by requiring prosecutors prove probable cause in a preliminary hearing.
Preliminary hearings, also called probable cause hearings, usually occur early in a criminal case. During these hearings, the prosecution must establish they had probable cause to justify the charges being brought. Probable cause is a very low standard, essentially requiring the prosecution to prove that they had reason to believe there was a “substantial chance” the defendant committed the crime at issue. Illinois v. Gates, 462 U.S. 213 (1983). This standard is very low, and the prosecution can bring evidence to a preliminary hearing that would be excluded during the trial phase. The judge will listen to the evidence and decide whether the standard has been met. If the prosecution can show that they have in fact met the burden of probable cause, then the case may proceed, potentially to trial. The defendant has the right to an attorney and to perform a full cross-examination of any witnesses the prosecution may bring to testify. If the Prosecution fails to establish probable cause, then the judge will dismiss the case. The prosecution will usually succeed in proving probable cause.
These hearings play an important role in preventing frivolous trials and protecting the defendant’s Fourth Amendment rights. A defendant may waive their preliminary hearing; however this is something that should be considered carefully. These hearings may serve to inform the attorney and defendant of potential testimony the prosecution might bring. In some cases, the defendant could win their case in the preliminary hearing, if the prosecution is insufficiently based. For these reasons, it is in every defendant’s best interest to think carefully about their rights and discuss the best course of action with their attorney.