For a police officer to stop the operator of a motor vehicle, the officer must have “reasonable and articulable” suspicion that a violation occurred. That means the suspicion must be objectively reasonable and that it must be able to be articulated, or explained.
After the stop, the officer’s level of suspicion must rise to “probable cause” to arrest the operator of a vehicle or vessel. The taking of a blood, breath or urine sample must be a search incident to an arrest, based on probable cause. If either the stop or the search was improper, the evidence may be excluded at trial.
Your right to a lawyer
States differ on when your right to consult a lawyer begins. Some states do not allow you to talk to a lawyer before deciding whether or not to take a blood, breath or urine test; other states allow such consultation. It is important to listen to the “advice of rights” given to you by the arresting authority. Those rights will advise you of your right to speak to an attorney at various times during the process. You may ask the arresting officer reasonable questions regarding the rights you have. If you have been misinformed, a competent lawyer will be able to remedy the problem.
In general, once your right to freedom has been restricted, you have the right to counsel. That right to counsel may or may not be applicable to your obligation to take a blood, breath or urine test. That depends on the jurisdiction (state) in which you are charged.
Of course, after you have been charged, you are entitled to consult with a lawyer. It is very important that you be completely candid and truthful with your lawyer. In alcohol-related offenses, often the things you think are the most damaging are actually the most helpful to your lawyer.