Skip to main content
Please enter a legal issue and/or a location
Begin typing to search, use arrow keys to navigate, use enter to select

What is Reasonable Suspicion for a DUI Stop?

Although DUI checkpoints remain a controversial exception to the rule (in most states), police officers can generally stop motorists only when they have reasonable suspicion of criminal activity. An officer who has reasonable suspicion that a crime has taken place may stop and briefly detain an individual for the purpose of a limited investigation. If the officer still suspects the motorist of DUI after the initial investigation, the officer will then usually carry out a field sobriety test and/or a BAC (breathalyzer) test.

This all means every arrest for drunk driving begins with an officer's reasonable suspicion that the motorist was involved in some sort of criminal activity, even if that turns out not to be the case. Even if a motorist is intoxicated while driving, a DUI case against him could be dismissed if the officer did not have reasonable suspicion for the initial stop.

Examples of Reasonable Suspicion for a DUI Stop

Reasonable suspicion that a motorist is impaired may by established by any of the following observations:

  • Straddling the center line
  • Illegal turn
  • Drifting from one lane to another
  • Nearly hitting other cars or objects on the roadside
  • Extremely slow or erratic driving
  • Frequent braking
  • Stopping in the middle of the road for no apparent reason

This is by no means a complete list, as anything an officer believes is a sign of impaired driving might possibly be considered reasonable suspicion. Likewise, an officer may investigate further if he has a reasonable suspicion that the driver is impaired after making a stop for something entirely unrelated (a burned-out brake light, for example).

In some cases, reasonable suspicion for a DUI stop may be established even if the officer did not witness any actual driving. For example, an officer may conduct a field sobriety test after an automobile accident or if a motorist is found unconscious behind the wheel of a parked car.

Reasonable Suspicion vs. Probable Cause

While reasonable suspicion allows an officer to temporarily stop and detain a motorist in order to investigate further if the officer thinks the motorist may have committed a crime, an officer must meet the higher standard of probable cause before making an arrest.  Probable cause simply means that an officer has enough evidence to believe a motorist has probably committed a crime, thus justifying his or her arrest. In the context of a DUI stop, an officer could have probable cause for an arrest after administering a field sobriety test and/or a breath test if the results point to probable intoxication. 

Probable cause differs from reasonable suspicion in that, in order to meet the probable cause standard, an officer must have enough evidence to suggest that the motorist has most likely committed a crime.  Reasonable suspicion, on the other hand, only necessitates that the officer have some indication that the motorist might have committed a crime.  It is a fine distinction, but an important one.

Did the Officer Have Reasonable Suspicion for Your DUI Stop? Ask an Attorney

Whether this is your first DUI or your third, having a skilled attorney in your corner can mean the difference between getting the maximum penalty and potentially having your charges reduced or dropped. If you have questions about the legality of the initial traffic stop or how to handle your case, it's in your best interests to contact a DUI attorney near you.

Was this helpful?

Thank you. Your response has been sent.

You Don’t Have To Solve This on Your Own – Get a Lawyer’s Help

Meeting with a lawyer can help you understand your options and how to best protect your rights. Visit our attorney directory to find a lawyer near you who can help.

Or contact an attorney near you:

Next Steps

Contact a qualified DUI attorney to make sure your rights are protected.

Begin typing to search, use arrow keys to navigate, use enter to select

Help Me Find a Do-It-Yourself Solution

Can I Solve This on My Own or Do I Need an Attorney?

  • Complex DUI situations usually require a lawyer
  • DUI defense attorneys can challenge Breathalyzer/Intoxilyzer or blood test results
  • A lawyer can seek to reduce or eliminate DUI penalties
  • A lawyer can help get your license back

Get tailored advice and ask your legal questions. Many attorneys offer free consultations.


 If you need an attorney, find one right now.

Copied to clipboard

Find a Lawyer

More Options