Is a blood draw within the scope of implied consent reasonable under the Fourth Amendment?

^3. The People contend that where a defendant opts for a blood test under California's implied consent law, the resulting blood draw is within the scope of that consent, and is therefore reasonable under the Fourth Amendment. Not so. A search conducted pursuant to a warrant is not per se reasonable. (People v. Cook (1978) 22 Cal.3d 67, 97, 98 ["[A] search conducted under color of a warrant is not 'reasonable per se,' but may be unreasonable in the constitutional sense on a number of grounds," for example, "even if the warrant is both legally sufficient and properly served, the search is unreasonable when it is excessive in intensity or duration"].) Likewise, even if a defendant consents to a blood test under California's implied consent law, such consent does not obviate the requirement that the blood test be conducted in a constitutionally reasonable manner. (See Schmerber, supra, 384 U.S. at pp. 767-768.)