'Show-me' the Facts: The Case for Warrantless Blood Tests in DWI Arrests Commentary
'Show-me' the Facts: The Case for Warrantless Blood Tests in DWI Arrests
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JURIST Guest Columnist Brendan Block, Saint Louis University School of Law Class of 2013, argues for exigency to apply to driving while intoxicated (DWI) suspects to allow for warrantless blood tests…


After working in a southwest Missouri prosecutor’s office last summer, I learned one of the harsh realities of DWI cases that some judges will not convict alleged drunk drivers without any blood-alcohol content evidence. Missouri’s slogan is the “show-me state.” No matter how many signs police may observe of a driver’s intoxication, blood-alcohol content is the most probative evidence in DWI cases.

The US Supreme Court’s grant of certiorari in Missouri v. McNeely may ensure that the prosecution provides the necessary blood-alcohol evidence in every DWI case. Instead of police taking drunk drivers to the police station to wait for a warrant for a blood test, they will be allowed to take drivers immediately to health clinics to get a blood draw by a medical professional.

In McNeely, a Missouri State Trooper took McNeely to a health clinic for a warrantless blood draw. The test results revealed a .15 blood-alcohol content (BAC). This was after the officer arrested McNeely because of his slurred speech and problems walking, and did not want the crucial evidence to dissipate.

In criminal law, exigent circumstances allow officers to circumvent the warrant requirement in specific instances. Courts have defined exigent circumstances as “an emergency situation requiring immediate action or urgency to prevent imminent danger to life or serious damage to property, or to forestall the imminent escape of a suspect, or destruction of evidence.” The Missouri Supreme Court held that, absent any other special facts to the DWI arrest, no per se exigency exception to the warrant requirement exists for the dissipation of alcohol in the blood stream alone. In assessing the exigent circumstances, the court relied upon Schmerber v. California, which found a DWI exigency exists when the dissipation of alcohol in the blood stream couples with extra facts such as an accident or hospitalization.

The Wisconsin Supreme Court came to a different conclusion than their Missouri counterparts in State v. Bohling, and held a common-sense rule for all DWI’s. They found the dissipation of alcohol from a person’s blood stream by itself creates a sufficient exigency to justify a warrantless blood draw. The court sets the limits to the rule that a law enforcement officer must order the blood draw from a person lawfully arrested for a drunk-driving related crime, when there is a clear indication the blood draw will produce evidence of intoxication. The court states that a “well recognized exigent circumstance is the threat that evidence will be lost or destroyed if time is taken to obtain a warrant.”

This loss of evidence exigency requirement commonly occurs with the readily disposable nature of illegal drugs. Although not illegal, alcohol is a drug. Additionally, alcohol has more dangerous effects to other people than illegal drugs like marijuana or cocaine, because more than two-thirds of Americans drink alcohol and many inevitably get on the roadways. In 2010, 10,228 people died in alcohol-impaired driving crashes, accounting for nearly one-third, or 31 percent, of all traffic-related deaths in the US. The annual cost of alcohol-related crashes totals more than 51 billion dollars. As for the loss of evidence, alcohol dissipates from the body at a rate of between between .02 and .04 units per hour. To date, the Supreme Courts of Wisconsin, Oregon and Minnesota recognize the dissipation of alcohol in the blood stream as an exigent circumstance.

Given the continued dangers of drinking and driving, a national per se exigency in DWI arrests would have a powerful deterrent effect. If society is serious about preventing drunk driving and saving lives, we must be serious enough to enforce it with as few loopholes for defendants and with the most reliable evidence possible. Defendants routinely challenge the accuracy of breathalyzer test results that are not as precise as blood tests. On the other hand, the exigency would end the confusion that often arises from the use of breathalyzers. Without exigency, however, the current policy [PDF] “actually requires police officers to stand by and allow the best, most probative evidence to be destroyed during a drunk-driving investigation.”

Most importantly, the US Supreme Court already has precedent to grant a per se exigent circumstance for DWI arrests in Welsh v. Wisconsin. In this 1984 Supreme Court case, the facts are similar to McNeely where the sole exigency was the dissipation of the driver’s blood alcohol content. The driver swerved off the road into an open field, ran to his house and went to bed. Without first securing a warrant, police entered petitioner’s home to arrest him for a DWI. The decision assessed the claims of exigent entry under the “gravity of the underlying offense” and “the penalty that may attach” under state law. At the time, the Court rejected this need to preserve evidence argument because in Wisconsin, society and the legislature only desired to punish offenders with a civil forfeiture of $200.

Twenty-eight years after Welsh, states ubiquitously punish DWI’s with jail time and significant fines. In Missouri, a first-time DWI is a class B misdemeanor, carrying a maximum punishment of six months in jail. In addition, Missouri requires a driver with above a .2 BAC to spend at least five days in jail. Because the BAC levels form a foundation to the punitive goals of the statute, accurate BAC evidence is even more crucial to enforcement. The legislature and society treat the enforcement of DWI’s much more seriously than Wisconsin in 1984, and thus, the US Supreme Court should now find a per se exigency in DWI arrests.

Valid concerns arise in opposing warrantless blood draws in DWI arrests. One concern is the absence of the warrant requirement and erosion of one’s Fourth Amendment rights. A rule like Wisconsin’s would not allow a blood test without observations of “clear” intoxication. This limit of police officer discretion is crucial to prevent arbitrary tests. Also notable is the concern that permitting warrantless testing for alcohol could open up avenues of other warrantless drug testing. The Fourth Amendment would be eroded if we lived in a society where an officer could test anyone walking down the street for drugs. However, drunk driving is unique and should be the only basis for warrantless testing because it involves a significant risk of harm to other people — whereas ordinary drug use only harms the individual.

Everyone deserves to be shown the proof of their intoxication, not just hear the officer’s observations at their trial. Potentially, McNeely will provide a national standard to ensure the most probative and accurate evidence of intoxication is allowed in every arrest. Bohling, Welsh and the exigency generally granted for the destruction of evidence have paved the way for the Supreme Court to allow a per se exigent circumstance in a DWI arrest. Therefore, in the interest of reliable convictions, and to eradicate the uncertainty in DWI law, warrantless blood tests will guarantee the most effective enforcement of DWI laws.

Brendan Block is pursuing a certificate in Health Law and has participated in Moot Court and the Health Law Association.

Suggested citation: Brendan Block, ‘Show-me’ the Facts: The Case for Warrantless Blood Tests in DWI Arrests, JURIST – Dateline, Dec. 5, 2012, http://jurist.org/dateline/2012/12/brendan-block-dwi-arrests.php.


This article was prepared for publication by Leigh Argentieri, a senior editor for JURIST’s student commentary service. Please direct any questions or comments to her at studentcommentary@jurist.org


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