Suppressing Chemical Test Results

You were arrested on suspicion of driving under the influence and told you were required to submit to a chemical test of your breath or blood. You may have also been told you had no right to speak with an attorney before deciding whether to submit to one or the other.
There may be legal grounds under the Fourth and 14th Amendments to the United States Constitution to suppress the test results from evidence. The seminal case of Missouri v. McNeely has spawned several challenges to the use of this evidence.
Absent “lawful consent” or “exigent circumstances,” the police must get a warrant before having someone stick a needle in you to draw blood. The same may apply to breath test samples though the law is a little less certain in this area (courts are presently grappling with this issue). What is “lawful consent?” Consent that is uninformed or coercive is not lawful consent, so if the police failed to inform you that there is an option to refuse, or put undue pressure on you to submit, that may well be a basis to have the evidence thrown out of court. What constitutes “exigent circumstances” depends on the “totality of the circumstances,” but the mere natural dissipation of alcohol is not enough to excuse the warrant requirement.
You should have an attorney review the police report in your case and discuss these issues with you before pleading guilty, and make sure the lawyer you talk to is knowledgeable about these issues.
I am a Board-Certified DUI defense attorney practicing in the Northern California Bay Area for the past 30 years. Feel free to contact me about your case.