There are many regulations that you must follow when you drive a motor vehicle. But the same is true for police officers. Before you are even pulled over for suspected drunk-driving, the police officer has to have a reason to stop you. This is what is known as probable cause.
If it is found that the police officer did not have sufficient means to stop you, any evidence, accept observations of driving must be suppressed in court.
But probable cause does not only apply to the officer stopping you. The officer must have sufficient evidence (through the use of field sobriety tests and questioning) in order to have detained you.
Probable cause also relates to the arrest process. Did he or she have probable cause to arrest you? Did the offense happen in the officer’s presence? If it is found in court that there was no probably cause for the arrest, any evidence that was obtained after the arrest is subject to suppression. This may include the chemical test failure or refusal to submit to a chemical test.
The prosecution must prove that there was sufficient evidence for your stop, detainment and arrest. Only an experienced DUI attorney knows the right questions to ask.