In 2013, the United States Supreme Court heard a landmark case in Missouri v. McNeely. In McNeely, the Supreme Court held that under typical circumstances, the Fourth Amendment prevented police from taking a blood sample without first obtaining a warrant.
Prior to that case, the state of Missouri had argued that it could require people accused of driving while intoxicated to give blood samples without obtaining a warrant. This decision was a major victory for defendants and requires that officers obtain a warrant from a judicial authority before engaging in a blood draw, which the Supreme Court noted is an invasive procedure.
In contrast, the United States Supreme Court has held that states can punish individuals who refuse to take a breath test, even if there is no warrant, in Birchfield v. North Dakota, since the breath test is less intrusive.
For more information on DWI and warrantless searches, please contact Scott A. Hamblin at (573) 635-7166 or email@example.com.