The Fourth Amendment of the Constitution protects you from unreasonable searches and seizures of your property and person. Generally speaking, this means that authorities may not conduct a search, seize your property or arrest you without first obtaining a warrant. However, the law applies differently when you are driving your car.
An arrest for a serious traffic violation, such as DUI, is a seizure in the eyes of the law, as is the traffic stop that often proceeds it. However, because it would be impractical to obtain a warrant before pulling a driver over, a different standard applies to traffic stops. A law enforcement officer cannot pull your vehicle over without reasonable suspicion that you are driving under the influence or have committed some other crime. Similarly, there must be probable cause for the officer to arrest you. However, both of these actions can take place without a warrant if reasonable suspicion and probable cause are present.
Differences Between Reasonable Suspicion and Probable Cause
Reasonable suspicion is grounds for a traffic stop. In other words, the officer must be able to demonstrate objectively that he or she had a valid reason for suspecting you of committing DUI or another crime.
However, reasonable suspicion alone is not sufficient to justify an arrest. For that, an officer has to gather facts supporting his or her suspicion that you may have committed a crime. If the officer succeeds in gathering the necessary evidence, that is probable cause.
As an example of how reasonable suspicion and probable cause function, imagine that you have been driving erratically. Your erratic driving provides the officer with reasonable suspicion that you may be under the influence, allowing him or her to pull you over. After pulling you over, the officer may notice your slurred speech, strange behavior and the smell of marijuana and/or alcohol on your breath or in your car. These signs alone may give the officer probable cause to arrest you, but he or she may choose to gather further evidence with breath testing or field sobriety tests. If there is sufficient probable cause, the officer may arrest you.
Examples of Reasonable Suspicion
Behavior that suggests driver impairment, such as lane drift, center line straddling, frequent braking or nearly missed collisions, may provide reasonable suspicion for an officer to pull you over. However, reasonable suspicion need not necessarily relate to impairment. If you speed or run a stop sign, the officer may pull you over without necessarily suspecting you of DUI. Nevertheless, if you exhibit signs of possible intoxication when the officer pulls you over, that may be probable cause to make a DUI arrest.
If you are pulled over and arrested without reasonable suspicion and/or probable cause, you may be able to obtain legal recourse. Contact a DUI lawyer in San Francisco, CA for more information.
Thanks to the Morales Law Firm for their insight into criminal law and reasonable suspicion for a DUI.