In 1966, the United States Supreme Court in Schmerber v. California was confronted with the issue of whether drawing blood from a DUI suspect over his objection constituted a violation of the Fourth Amendment. In that case, the suspect had been taken to a hospital for a blood draw; the suspect refused to consent to the test, but did not resist as a physician withdrew a sample.
The Court affirmed the conviction, holding that a nonconsensual draw without a warrant was constitutionally permissible under the circumstances. But in doing so, the Court clearly distinguished the circumstances which made it permissible:
...Finally, the record shows that the test was performed in a reasonable manner. Petitioner's blood was taken by a physician in a hospital environment according to accepted medical practices. We are thus not presented with the serious questions which would arise if a search involving use of a medical technique, even of the most rudimentary sort, were made by other than medical personnel or in other than a medical environment — for example, if it were administered by police in the privacy of the stationhouse. To tolerate searches under these conditions might be to invite an unjustified element of personal risk of infection and pain....
The state will argue that the cops sticking you with a needle have taken a course and obtained a medical certification. Can that possibly be enough? Consider the Schmerber Court's final admonition:
We thus conclude that the present record shows no violation of petitioner's right under the Fourth and Fourteenth Amendments to be free of unreasonable searches and seizures. It bears repeating, however, that we reach this judgment only on the facts of the present record. The integrity of an individual's person is a cherished value of our society. That we today hold that the Constitution does not forbid the States minor intrusions into an individual's body under stringently limited conditions in no way indicates that it permits more substantial intrusions, or intrusions under other conditions. 348 U.S. 771
This needs to be tested in the appeals courts, and soon. Before someone gets hurt or dies:
Ignoring the pain, injury and infection aspects for the moment, bear in mind that: the blood must be taken from a vein, not an artery (which has a higher blood-alcohol concentration); the skin must be swabbed with an approved antiseptic (not isopropyl alcohol, which can raise the blood-alcohol concentration); the correct amount must be taken, with no contamination from the officer; it must be placed in a sterile and sealed vial; an approved preservative in the correct amount must be added and mixed in (to prevent fermentation, which increases BAC); an anti-coagulant (to prevent clotting, which increases BAC) must also be added, again in the correct amounts; etc.....