Perhaps you were driving to your destination minding your own business when the patrol car behind you turned on its lights and sirens warning you to pull over. You knew that you often drive mindlessly since you know the roads well, so you aren't sure what you did. Maybe you were speeding or forgot to signal as you changed lanes.
In any case, your thoughts then turned to the couple of drinks you had with friends before heading home. You never thought you weren't capable of driving safely, but you know that may not matter if the officer smells alcohol on your breath.
Could the officer arrest you?
Under the Fourth Amendment to the U.S. Constitution, a police officer must establish probable cause before arresting you. Even though court decisions have narrowed down what this constitutes, grey areas continue to exist. Probable cause constitutes those bits of evidence that an officer believes indicate you committed a crime. For example, if the officer smells alcohol on your breath, it could potentially indicate drunk driving.
The officer may then ask you to submit to field sobriety tests to gain further evidence of his or her suspicion. As an aside, you are not legally obligated to participate in these tests. However, if you do and the officer says you failed, it could provide the officer with the probable cause he or she needs to arrest you. The same could be said for a roadside breath test. With enough evidence that you committed the crime of drunk driving, you could end up under arrest.
Did the officer really have probable cause?
Not participating in field sobriety tests may not keep you from finding yourself in the back of a police car. However, once you are able, you can challenge your arrest, which is often the first part of a criminal defense. Just because the officer believed he or she had probable cause does not make it legally true. After reviewing your circumstances, errors could arise that put the arrest into question.
Ultimately, a judge makes the determination regarding whether enough alleged evidence existed to substantiate your arrest. If not, it could have violated your rights under the Fourth Amendment. Of course, this is just one aspect of your encounter with the police that could come under review as part of your defense. Police officers must adhere to certain protocols, and if they deviate from them, it could substantially affect the outcome of your case.