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Do police always need probable cause?

Most of us have heard the phrase “probable cause” used by police officers and prosecutors on television shows. The first thing any good criminal defense lawyer will do is investigate whether the police had right and reason for searching a person’s property, or even questioning a person before making an arrest. In this post, I will explain the concept of probable cause and why it is such an important component of our criminal justice system.

Constitutional rights

Probable cause falls under the umbrella of the Fourth Amendment to the Constitution, ensuring our rights against illegal search and seizure. The actual sentence reads,

“…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.”

In short, it is the Fourth Amendment that protects us from police entering our property to search for evidence of a crime, unless they have a warrant…sort of. In reality, the Supreme Court of South Carolina and the U.S. Supreme Court have ruled in several cases over the years, giving police the right to seize evidence and make an arrest without the need for a warrant. Each case, however, relates to a very specific set of circumstances. Not surprisingly, police often make a mistake in judgment and unwittingly violate the rights of the individual.

Warrants, probable cause and traffic stops

The first line of defense for alcohol-related driving offenses in South Carolina is often challenging the arresting officer’s probable cause for making the traffic stop. But by very definition taken directly from the Fourth Amendment language, police can’t possibly have a warrant “ particularly describing the place to be searched ” when pulling a driver over for suspicion of driving under the influence (DUI) or driving with unlawful alcohol concentration (DUAC). This seems contradictory to our constitutional rights.

To understand what police gives police the right to make a traffic stop to test for blood alcohol concentration (BAC), it is important to understand that driving is a privilege conferred by the State of South Carolina. It is not a legal right. Police are sworn to uphold the law and to protect the citizenry from potential danger and criminal acts. By extension, police are granted the right to pull over a car anytime they witness (or have a report of) erratic or unlawful behavior by the driver, which may put the driving public in danger.

In case you are wondering whether the limits of probable cause have been tested in the courts; they have. In Illinois v. Gates, the U.S. Supreme Court ruled that police only need to believe a ‘ substantial chance ’ or a ‘ fair probability ’ of a criminal act is present. As you might expect, the vagueness of the language is often what comes up for argument in court.

A fine line , but not really

But at the traffic stop, police may misinterpret the extent and limits of their authority. The courts have ruled that police may search and seize an individual’s property (including the car) without a warrant in the cases when they witness or suspect a crime is being committed or may be committed. However, they may not search a vehicle for evidence based only on an unreasonable hunch. For example, if they do search a trunk at the scene of the traffic stop and seize contraband unrelated to the DUI arrest, an experienced defense attorney might successfully argue the evidence cannot be used by the prosecution for any additional charges that may result.

If you are facing criminal charges and you believe your Fourth Amendment rights have been violated, I urge you to call my office right away.