Ability to force DWI blood tests in Texas limited by court decisions

In 2009, Texas lawmakers passed legislation requiring police officers to conduct warrantless blood tests on drivers arrested for driving while intoxicated (DWI), but only in specific situations. For instance, police were permitted under this law to perform mandatory blood tests when they had "reliable information from a credible source" that the driver in question had two or more previous DWI convictions.

However, a recent U.S. Supreme Court case - not to mention several opinions issued by Texas courts - recognized that these mandatory blood tests may be unconstitutional unless a warrant is first obtained or exigent circumstances exist.

The impact of Missouri v. McNeely

The dispute regarding warrantless DWI blood draws in Texas stems not only from the recent U.S. Supreme Court case - Missouri v. McNeely - but also from Texas' implied consent law and the state's mandatory blood draw statute.

Essentially, the implied consent law in Texas states that anyone arrested for a DWI is already deemed to have given consent to BAC testing simply by driving a motor vehicle within the state. While a driver is certainly free to refuse testing if arrested on DWI charges - and face a license suspension if he or she does so - the state's mandatory blood draw statute previously permitted police to force a blood test if the driver had two or more DWIs. Importantly, this mandatory blood test could be performed even if the driver initially refused testing and no warrant was obtained.

In Missouri v. McNeely, the Supreme Court noted that warrantless blood tests such as these are only permissible if they fall within a recognized exception to the Fourth Amendment's search warrant requirement. One such exception is the presence of an exigent circumstance, which can include an unusual situation that demands immediate action in order to avoid the loss of important evidence.

Ultimately, the Supreme Court determined that the mere fact that alcohol may dissipate in an individual's system over time does not, by itself, establish an exigent circumstance that would allow a warrantless search. Instead, the Court declared, exigent circumstances must be assessed case by case based upon the totality of circumstances.

Even though this particular opinion did not directly declare Texas' mandatory blood draw statute as unconstitutional, several Texas courts have applied the ruling to Texas cases. Indeed, Texas courts have already recognized that the state's mandatory blood draw statute is no longer a valid exception to the warrant requirements of the Fourth Amendment. Although, it should be noted that police can still conduct warrantless blood tests on drivers with two or more previous DWIs if exigent circumstances exist, pursuant to McNeely.

While these recent opinions certainly bolster the Fourth Amendment rights of drivers in Texas, they also illustrate how ever changing the law can be when it comes to warrantless searches. Consequently, if you are currently facing DWI charges in Texas, it is crucial to contact an attorney who is not only experienced with criminal defense but also familiar with any relevant changes to the state's drunk driving laws.