DUI and Reasonable Suspicion

You may have heard of the legal term reasonable suspicion. This is an important term for any citizen to understand, although it also plays an important role in DUI cases. This guide will explain everything you need to know about reasonable suspicion in the context of a DUI. If you have any legal questions, it is always a good idea to speak with an attorney.

Reasonable Suspicion

Reasonable suspicion is something that police officers need to have prior to investigating a citizen for a crime. If there is no reasonable suspicion, then officers need a search warrant to invade a citizen’s privacy in search of wrongdoing. However, if there is reasonable suspicion, any officer is legally allowed to enter someone’s home, search someone’s car, or do other things that would normally be illegal. In a DUI case, reasonable suspicion is needed in order to pull a car over.

So what is reasonable suspicion? It is exactly what it sounds like. It is essentially just a reason to be suspicious of someone. For example, if a home has bullet holes in a window, that may serve as reasonable suspicion and give officers the right to investigate to ensure no violent crime was committed inside. Reasonable suspicion in a DUI case may include:

  • Erratic driving
  • Colliding with objects or other vehicles
  • Driving very slow or fast

While reasonable suspicion is needed to begin an investigation, it is not enough to make an arrest. For that, an officer will need probable cause.

Probable Cause

Similar to reasonable suspicion, probable cause is needed to place someone under arrest. Probable cause is evidence that some crime was committed. Simply suspecting that a crime was committed is not enough. It is a right of all citizens to only be arrested when there is evidence of wrongdoing. In a DUI case, examples of probable cause include:

  • The smell of alcohol
  • Drunken behavior
  • Empty alcohol containers
  • An admission of guilt
  • A failed sobriety test

So, to put reasonable suspicion and probable cause together, this is how an arrest must be made. First, an officer must notice something strange, which gives him or her reasonable suspicion. Only after reasonable suspicion is established, the officer may begin to investigate. If probable cause is discovered, then the officer may make an arrest. Otherwise, the citizen must be free to go. If this does not happen, in this order specifically, then you may have a strong case to have the charges dropped. Speak with a DUI lawyer in Fairfax, VA to learn more.


Thanks to May Law, LLP for their insight into criminal law and reasonable suspicion in a DUI.