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How Are Blood Search Warrants Legal?


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Now that the holiday season is upon us, we’re bound to hear more and more about “No Refusal” Weekend initiatives.  Whenever you hear about Blood Warrants in DWI cases, I’m often asked “how can the police get away with this?” We as a society presume the police wouldn’t do anything unlawful, and I have to say, most police officers wouldn’t. 

But many times they do. We presume that it’s legal for the government to forcibly take someone’s blood, but we don’t know why.  This post intends to educate the reader on the law of “No Refusal” weekends and blood search warrants in DWI cases.  This will include citations to case law and Texas statutes for you to look up if you’re interested in the reading.  As always, I encourage you to comment or ask me any questions you have.

The first question that has to be answered is whether taking someone’s blood is a search under the Fourth Amendment of the US Constitution.  Fourth Amendment jurisprudence holds that if there exists a reasonable expectation of privacy in the area to be searched, then a warrant is required.   Certainly we all agree that we have a reasonable expectation in our own body/blood.  However, it took the United States Supreme Court in 1966 to finally make that finding in what is now the landmark case of Schmerber v. California (384 U.S. 757) (1966).  Schmerber stated conclusively that taking a person’s blood is a search.  This is important for a number of reasons.  First, it meant that police had to follow Fourth Amendment law before taking your blood.  This is the text of the Fourth Amendment:

“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”


The Fourth Amendment requires that before police can conduct a search, they must secure a warrant.  A warrant cannot be issued unless probable cause exists supported by oath or affirmation.  “No Refusal” Weekends were born in 1966 with the Schmerber decision.

All states do not conduct blood draws through search warrants in DWI cases.  Texas law expressly permits them.  Our “Schmerber” decision came when the Texas Court of Criminal Appeals decided Beeman v. State (86 S.W.3d 613) in 2002.  The Texas Court of Criminal Appeals is the highest court in Texas that hears criminal cases.  Beeman held that our implied consent law did not preclude police from seeking a search warrant for blood in DWI cases.  The implied consent law (Chapter 724 of the Texas Transportation Code) states that whenever we accepted our Texas Driver’s License we impliedly consented to provide a sample of breath or blood if we’re ever requested to do so by a police officer.  This is why whenever you’re arrested for a DWI, your DL is confiscated if you refuse or blow over a .08. An Administrative License Revocation hearing is necessary to keep your license before the disposition of the DWI case. The defendant in the Beeman case argued it was unreasonable to permit a search warrant blood draw in a DWI case because the implied consent law already accounted for how officers were supposed to obtain a sample.  Instead, the Court of Criminal Appeals stated that reasonableness was not an issue because police can seek a search warrant in any criminal case from a neutral and detached magistrate and once issued, reasonableness becomes moot.  This holding opened the proverbial floodgates for police in Texas to seek a search warrant in every DWI case.

The law that permits these warrants also restricts them.  Hiring the right DWI lawyer is critical in defending these cases because he/she must know how the law applies.  After you have refused to provide a sample of breath or blood, an officer must apply for a search warrant with a judge by describing in a sworn affidavit what probable cause exists for the offense and where the evidence may be located.  The Texas Code of Criminal Procedure (in Article 18.01(b)) states that a search warrant must be based on probable cause as determined within the four corners of the Affidavit.  This means the officer must detail precisely what evidence exists to believe the person may be intoxicated in writing. Texas case law defines probable cause as, “under the totality of the circumstances, there is a fair probability that contraband or evidence of a crime will be found at a specific location.”  An effective way to combat and have blood tests excluded is by attacking the officers’ affidavits as lacking probable cause on its face.  This occurs when an officer doesn’t provide enough information in writing to rise to the level of probable cause.  Another way to attack the warrant is to argue that the magistrate is not neutral and detached if evidence exists showing they may be biased.  I know judges who have fax machines in their homes for police to fax them affidavits in the middle of the night so they may review them and approve or deny.  In Austin, there are judges present at the jail booking facility twenty-four hours a day, seven days a week.  These factors alone are not sufficient to attack the magistrate.

Now you know the history of how blood search warrants came into being such a prevalent part of DWIs.  Summing up, the Fourth Amendment prohibits unreasonable searches and seizures, but searches conducted pursuant to a warrant will rarely require any deep inquiry into reasonableness so long as the warrant is issued by a neutral and detached magistrate.