Michael A. Ferraro, Esq., P.C.
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What is probable cause in a DUI investigation?

On Behalf of | Aug 2, 2022 | DWI defense |

Driving under the influence (DUI) is both dangerous and illegal. If you are caught and convicted, you may face a range of legal and collateral repercussions depending on the severity of the charge.

However, to legally stop you for a DUI investigation and subsequent arrest, the law enforcement must have probable cause that you are drunk driving. An arrest without probable cause can form the basis of your DUI defense.

So what is probable cause and how is it established?

Probable cause refers to the reasonable belief that an individual has, is or will be committing a crime. This belief must be factual rather than a hunch or mere suspicion. Thus, to establish probable cause during a DUI stop, the officer must specify objective circumstances that made them believe the motorist in question must be drunk behind the wheels. They cannot establish probable cause by simply saying something like, “I just had a hunch that you might be drunk.”

Circumstantial facts that can be used to establish probable cause include:

  • Zigzagging or weaving across the road
  • Dangerously accelerating and decelerating
  • Drifting in and out of the lane
  • Running through the stop sign

In other words, you must be breaking some traffic law for the police to stop and investigate you for drunk driving.

Probable cause and DUI stop

Once the police have established probable cause, they will stop and investigate you for drunk driving. Part of the investigation can involve interrogating or directing you to take a field sobriety and/or Breathalyzer test.

It is not uncommon for the police to ask questions like, “Have you been out drinking?” or, “How many drinks did you have?” While these questions may seem harmless, an affirmative answer to either question can land you in trouble. An admission that you have been drinking or that you just had one beer or a glass of wine can amount to self-incrimination, and the police will use this evidence against you during the trial.

A DUI conviction has serious consequences. If you are pulled over without probable cause, you may have grounds to challenge the legality of your arrest.