San Francisco DUI Lawyer Blog

 Posted on January 23, 2013 in DUI

Blood Test Results May Be Excluded From Evidence

Though California law enforcement agencies have long engaged in the practice of demanding blood draws from DUI arrestees without a warrant - at times even forcibly taking the blood by strapping suspects in a chair or holding them down on the ground - that practice may soon be deemed unconstitutional.

Earlier this month, the United States Supreme Court heard oral arguments in the case of Missouri v. McNeely . The legal issue presented is “whether a law enforcement officer may obtain a nonconsensual and warrantless blood sample from a drunk driver under the exigent circumstances exception to the Fourth Amendment warrant requirement based upon the natural dissipation of alcohol in the bloodstream?"

In layman terms, the question is whether such warrantless invasions of the body are allowed on the basis that alcohol, once absorbed and distributed in the body, begins to eliminate (i.e., “burn off").

The Supreme Court of Missouri held that law enforcement agencies may not do so where the opportunity exists for them to quickly apply for a warrant. Warrants may be obtained telephonically, so the delay is generally short if a magistrate is available and the police are not delayed by unusual circumstances.

The prediction here is that the high Court will deem routine warrantless blood draws in connection with drunk driving arrests to be unconstitutional unless the suspect is at least offered an opportunity to provide a breath sample instead. If drug use is suspected, law enforcement officers will need to first obtain a warrant unless there are unusual circumstances justifying an exception to the warrant requirement.

Expect a decision by this summer, and in the meantime, make sure your DUI defense attorney is aware of the possibility that blood-alcohol test results may be excluded from evidence if the decision affirms the Missouri Supreme Court’s ruling.