Although California case law allows police agencies to forcibly take a blood test from an uncooperative DUI suspect, most police agencies in Los Angeles county do not exercise this discretion. Normally, a person arrested for a DUI in Los Angeles county is given a choice of a breath test or blood test following arrest and if the suspect refuses, he or she is charged with a DUI with a refusal enhancement.
A refusal carries the potential for jail time at court and a one year mandatory license suspension from the DMV. However there are agencies in Orange County that routinely obtain blood samples from DUI suspects without consent. Irvine Police Department is one example. The law in California allows them to do this using reasonable force. The results of the blood test are still admitted into evidence at court and the defendant also faces the increased court and DMV penalties of a refusal.
However, forced blood samples may soon be a thing of the past. The US Supreme Court is currently considering the constitutional validity of the process in the case of Missouri v McNeely. At the heart of the discussion is a suspect's Fourth Amendment right against unreasonable searches and seizures.
The State of Missouri's argument is that a suspect's dissipating blood-alcohol content provides an emergency circumstance that justifies a warrantless drawing of blood without the suspect's consent. "The police are facing a destruction of critical blood-alcohol evidence, every minute counts and it's reasonable for the officers to proceed" argued Assistant Solicitor General Nicole A. Saharsky.
Countering the argument, Justice Sonia Sotomayor asked "How can it be reasonable to forgo the Fourth Amendment in a procedure as intrusive as a needle going into someone's body?"
Justice Ruth Bader Ginsburg said that it is relatively easy and quick for the police to obtain a warrant for a blood sample to be taken. If 30 minutes passes without a warrant, perhaps the officer could proceed, she suggested. It seems unlikely that police agencies will be allowed to routinely obtain forced blood samples without significant limits to their discretion.