In Missouri v. McNeely, the United States Supreme Court discussed when a blood draw without a warrant was permissible.

In the case, Tyler McNeely was stopped by a Missouri police officer after he was seen speeding and crossing over the centerline of the road. When he was stopped, McNeely was slurring his speech, he smelled of booze, and his eyes were bloodshot. He failed the field sobriety tests and refused to take the portable breath test. McNeely was then placed under arrest. He was taken to a hospital for a blood test after he indicated that he would refuse the breath test at the police station as well. McNeely was informed of the consequences of refusing to submit to the blood test under the state's implied consent law, but McNeely did not relent. The officer then obtained the blood sample without first obtaining a warrant. The sample showed McNeely's blood-alcohol level was over the legal limit. He was subsequently charged with a DWI.

McNeely moved to suppress the blood test evidence arguing that his Fourth Amendment rights were violated because the information was obtained without a search warrant. The trial court agreed with McNeely, that under the circumstances of his case, there was no reason the officer couldn't have gotten a warrant before the blood draw. The case was appealed and transferred from the Missouri Court of Appeals to the Supreme Court of Missouri. That court affirmed, relying on the U.S. Supreme Court Decision in Schmerber v. California. The court stated that Schmerber requires it to look at the totality of the circumstances when seeking to do a blood test without a warrant. The circumstances must be more than just "mere dissipation of blood-alcohol evidence." The court found no "special facts" to justify a warrantless blood test and ruled that McNeely's Fourth Amendment rights were violated under the circumstances of his case.

The U.S. Supreme Court agreed to hear the case in order to determine "whether the natural dissipation of alcohol in the bloodstream establishes a per se exigency that suffices on its own to justify an exception to the warrant requirement for nonconsensual blood testing in drunk-driving investigations."

The Court stated warrantless searches are generally only permissible if the fall into one of the recognize exceptions to the Fourth Amendment. Because a blood test is so invasive, the Court stated that an exception is needed to perform one without a warrant. One recognized exception is exigent circumstances. In exigent circumstances "'there is compelling need for official action and no time to secure a warrant.'"One exigency applicable in McNeely's case is to "prevent the imminent destruction of evidence." To determine if a situation is an exigent circumstance, courts look at the totality of the circumstances in each case.

Missouri argues that because blood alcohol dissipates a warrantless test is reasonable. The Court conceded that alcohol levels in blood do go down over time due to "the human body's natural metabolic processes." The Court also acknowledged that "a significant delay in testing will negatively affect the probative value of the results." However, the Court stated that "[i]n those drunk-driving investigations where police officers can reasonably obtain a warrant before a blood sample can be drawn without significantly undermining the efficacy of the search, the Fourth Amendment mandates that they do so." The Court notes there may be drunk driving cases where a getting a warrant isn't practical under the circumstances of the case. But the Court points out that is why a totality of the circumstances analysis is appropriate to judge if there was an exigent circumstance.

The Court states that there will always be some delay in obtaining a suspect's BAC because the police officers have to transport the suspect to a facility for the blood draw. In addition, the Court acknowledges that modern technology now permits police officers to obtain a warrant quickly, such as over the phone or electronically.

The Supreme Court affirmed the ruling of the Missouri Supreme Court in a 5-4 ruling, holding that "in drunk-driving investigations, the natural dissipation of alcohol in the bloodstream does not constitute an exigency in every case sufficient to justify conducting a blood test without a warrant."

If you have been arrested for DUI, even if a blood or breath tests was performed, there are many tactics an experienced defense attorney can take to challenge your arrest. Call the law office of Aaron Wolff at (425) 284-2000 or contact him online.