Every DUI arrest begins with a traffic stop. Police officers can't simply pull over a motorist because he or she feels like it. They have to have a reason. In fact, an officer must have "reasonable suspicion," which means that the officer has enough reason to believe that you may be committing a crime.
Substantiating a DUI traffic stop requires the officer to observe some sort of behavior that could indicate impairment. Without it, the stop may not meet the scrutiny of the court, and then any evidence gathered thereafter may not be admissible in a case against you for drunk driving.
What constitutes reasonable suspicion?
After a great deal of research from a variety of sources, law enforcement officials know that certain vehicle movements could indicate that a drunk driver is behind the wheel. Those actions include the following:
- Frequent braking
- Illegal turning
- Stopping in the middle of the road without a discernible reason
- Straddling the center line
- Driving erratically or extremely slow
- Drifting from lane to lane
- Almost hitting objects or vehicles on the side of the road
This list doesn't include all of the reasons why an officer may believe the driver of a vehicle is impaired, but these represent some of the most common. Of course, if an officer pulls you over for some other reason, such as a broken tail light, and smells alcohol, sees your eyes are bloodshot or witnesses you slurring your words, those actions could cause the officer to suspect you of drunk driving.
You need to know that reasonable suspicion does not have to meet the same threshold as probable cause. For reasonable suspicion to occur, the officer only has to have a belief, a sort of educated guess, that you might have committed a crime. On the other hand, establishing probable cause requires evidence that you probably committed a crime. For this reason, police officers ask you to participate in field sobriety tests and to submit to a breath test. If you "fail" these tests, that provides probable cause, along with any other suspect behavior.
Was there reasonable suspicion in your case?
The only way to answer that question is to review all of the circumstances surrounding the traffic stop and the events that led to your arrest on suspicion of DUI. If it turns out the officer failed to establish reasonable suspicion or probable cause, any so-called evidence of your impairment may not be admissible in court.