Wisconsin analyzes at length whether defendant impliedly consented and then actually consented, concluding that he did. State v. Brar, 2017 WI 73, 2017 Wisc. LEXIS 395 (July 6, 2017)*:
[*P35] Having concluded that Brar consented, we must determine whether his consent was voluntary. We conclude that Brar voluntarily, albeit impliedly, consented when he chose to drive on Wisconsin roads. And, his subsequent statement to the officer, re-affirming his previously-given consent was likewise voluntary. Brar does not argue otherwise; in essence, he contends that the voluntariness of his consent dissipated sometime after he had already consented.
[*P36] After consenting to the blood draw, Brar asked the officer if he needed to obtain a warrant to draw his blood. The officer shook his head no in response. However, the officer’s response did not vitiate the voluntariness of Brar’s consent.
[*P37] After all, the officer did not need a warrant because Brar already had consented. And, the officer was not obligated to explain further than he did; for example, an individual need not be informed of the opportunity to withdraw consent under Wis. Stat. § 343.305(3) in order for consent to be voluntary. See Schneckloth, 412 U.S. at 229 (reasoning, that requiring the State to “affirmatively prove that the subject of the search knew that he had a right to refuse consent, would, in practice, create serious doubt whether consent searches could continue to be conducted”). Even if the import of Brar’s question was unclear to the officer, “an officer need not clarify whether an ambiguous statement is meant to withdraw otherwise valid consent to search.” See State v. Wantland, 2014 WI 58, ¶47, 355 Wis. 2d 135, 848 N.W.2d 810. Accordingly, the officer accurately responded to Brar’s question and had no obligation to supply Brar with further information.