There is a good deal of debate in the legal community about whether warrantless blood samples taken from DUI suspects are constitutional following the U.S. Supreme Court’s decision in Missouri v. McNeely. The core of this debate is whether “implied consent” laws constitute an exception to the Fourth Amendment’s warrant requirement, or whether such consent is “involuntary consent” because it is based on the threat and imposition of a license suspension.
The McNeely decision did not invalidate “implied consent” statutes such as the operative one in California which is Vehicle Code section 23612. What the holding does make clear is that a drunk driving suspect may withdraw his or her implied consent (subject to being penalized with a license suspension). If the police have a blood sample forcibly taken without a warrant, or threaten to do so, then there is no lawful consent and the blood-alcohol or blood-drug evidence is subject to suppression under the federal exclusionary rule unless some other exception to the warrant requirement is established by the government.
The voluntariness of consent is measured by the “totality of circumstances.” Make sure you have legal counsel who is knowledgeable in this esoteric area of the law.
