Last year, the U.S. Supreme Court handled a landmark case for drugged and drunk driving cases. The nation’s top court ruled that law enforcement officials cannot involuntarily draw blood samples from people who refuse to comply with the test unless a warrant is acquired. Authorities would only be able to obtain a blood sample against an individual’s will under “exigent circumstances.” Of course, this ruling has the potential to invalidate evidence in driving under the influence cases throughout the country.
One of the most crucial aspects of the Supreme Court is that time isn’t an exigent factor. As such, police cannot leverage concerns about dissipating blood-alcohol or drug content to obtain warrantless blood evidence.
South Carolina law not only makes it illegal to drive while impaired by alcohol, but it also is illegal to drive while under the influence of drugs. The ABA Journal notes that alcohol metabolization rates are somewhat predictable, so prosecutors can calculate what a person’s blood-alcohol content was at the time of arrest. On the other hand, drugs generally do not metabolize in the same predictable way as alcohol.
Keeping this in mind, some criminal defense observers worry that future court cases will examine whether or not this fact alone creates an exigent circumstance, which would open the door to warrantless blood draws when drug use is suspected.
Criminal defense observers are also concerned about what constitutes impairment for drug use and whether or not blood tests are a reliable indicator. For example, a person’s blood test might show marijuana use, but that could be lingering from use that occurred well before a person decided to get behind the wheel. At the same time, there is no consensus about what blood content actually constitutes impairment for many types of drugs.
Clearly, defending against drug-related DUIs can be a tricky task. Developments from the Supreme Court as it regards warrantless blood draws only cloud this picture. Given the complicated landscape of impaired driving laws in South Carolina and across this country, offering a defense — especially when blood-draw evidence might not be admissible — could seem rather onerous.
Observers have noted a number of other questions still lingering after the high court’s decision. Some of those issues will be explored in the forthcoming blog post.
Source: ABA Journal, “SCOTUS ruling could complicate laws on impaired driving,” Lorelei Laird, April 1, 2014