Whether you have been stopped, investigated, or arrested for DUI police must have probable cause. Probable cause is the reasonable belief that some type of criminal activity has taken place. If an officer stops your car and does not have probable cause it may be possible to hire a DUI lawyer to have your DUI charges dismissed or reduced.
What if I am stopped without probable cause?
If an officer has stopped you without probable cause they have violated the Fourth Amendment of the United States Constitution which prohibits unreasonable searches and seizures. If this has occurred its likely you can have evidence gathered during the illegal stop suppressed, which means the court will rule the state is not allowed to use the evidence against you when trying your case.
The caveat, however, is that the officer does not have to have probable cause to believe you were intoxicated to make the stop. In fact, according to Terry v. Ohio, the United States Supreme Court decided the officer only needs "specific articulable facts" that a traffic infraction has occurred. So while the officer must have some reason to stop your car, it could be as simple as a broken taillight, running a red light or stop sign, weaving, or unusual stops and starts.
How can the police stop me at a sobriety checkpoint without probable cause?
One interesting point of contention which has been reviewed in recent years is the use of sobriety checkpoints. Most states allow sobriety checkpoints, often with very specific requirements, arguing the stop is not a criminal investigation but rather an administrative procedure. Strict constitutionalists have argued vehemently against such blurring of constitutional lines, but for now sobriety checkpoints are legal in many states.
Probable cause for DUI investigation and arrest
Not only does the police officer need probable cause to stop your car, they will also need additional reasons to begin a DUI investigation. A broken headlight will not be enough to initiate a DUI investigation.
For example, the officer will need suspicion of intoxication to ask you to submit to a field sobriety test or breathalyzer test. Evidence of intoxication could include blood shot eyes, slurred speech, opened containers of alcohol in your car, the smell of alcohol on your person, or your inability to walk. Consider, if you admit to drinking alcohol when questioned this is considered probable cause.
If the officer does not have evidence before he begins his DUI investigation the evidence obtained during a search, field sobriety test, or chemical test can be suppressed by the court.
Finally, if the police officer decides to make a DUI arrest they must have information and facts to substantiate probable cause. This information should also be outlined in the DUI arrest report. Having a suspicion of intoxication is not sufficient. You may also have additional protections if the officer arrests you, takes you into custody, and begins an official custodial interrogation.
Talk to a DUI lawyer if you believe an officer did not have probable cause to make a DUI stop, investigation or DUI arrest.