Highlights of Post

  • Police are required to get a search warrant before taking a blood sample from a DWI suspect.
  • However, no search warrant is needed to obtain a breath sample from a  DWI suspect.
  • States cannot prosecute DWI suspects for refusing to submit to a warrantless blood test.  But states can criminally punish DWI suspects who refuse to take warrantless breath tests.


Some background information first:

The U.S. Supreme Court addressed whether police can obtain breath and blood draws from suspected DWI motorists without a warrant.

All states have Implied Consent Laws  that require drivers arrested for DWI to provide either a blood or breath sample to determine the blood alcohol concentration (BAC) in their system.  If a motorist refuses to provide a specimen, then his or her license is usually suspended.

North Dakota and Minnesota take their DWI laws a step farther.  In these two states (and a few others), a driver who declines to provide a blood or breath specimen after being arrested for DWI is charged with a separate offense—refusal to provide a chemical test.

So what’s the problem?

The Supreme Court heard three DWI cases from North Dakota and Minnesota to determine if search warrants are required before taking either a blood or breath specimen from DWI suspects.

In the first case, Birchfield vs. North Dakota, Daniel Birchfield crashed his car into a ditch in North Dakota and was arrested for DWI.  He declined to provide a blood sample as required by North Dakota law and was then charged with refusing to provide a chemical test.  He pleaded guilty to refusing to provide a blood sample and appealed arguing that the refusal law violated his Fourth Amendment right against unreasonable searches.

In Bernard v. Minnesota, William Robert Bernard, was arrested for DWI after he got his truck stuck in the St. Paul River while trying to pull a boat onto land.  Officers read Bernard the Minnesota Implied Consent warning notifying him that it is a crime to decline a chemical test.  Bernard refused to provide a breath sample and was prosecuted for refusing to provide a chemical test.  The trial court initially dismissed the charge, but on appeal the charge was reinstated and this appeal follows.

In Beyland v. North Dakota Dept. of Transp., Steve Michael Beyland, was stopped for driving erratically and exhibiting signs of intoxication.  He was arrested for DWI and police read him North Dakota’s Implied Consent law advising him it was a crime to not provide a chemical test.  To avoid being charged with the offense of refusing to provide a chemical sample of his BAC, Beyland gave a blood sample that showed his BAC was .25.  Beyland’s license was administratively suspended (similar to ALR Hearings) for two years and he appealed.   On appeal he argued his consent to provide the blood test was coerced because he consented only to avoid being charged with the offense of refusing to provide a chemical test.


ISSUE:  Do police need a search warrant before obtaining a breath or blood specimen from a motorist lawfully arrested on suspicion of DWI?

DWI Car Crashes
Supreme Court determined that police (government) have a strong interest in preventing harm caused by drunk drivers.  This outweighs privacy concerns from obtaining breath specimens from suspected DWI motorists.

To answer this question, the Court balanced the privacy concerns that blood and breath tests raise against the government’s legitimate interest in protecting the public from the dangers caused by drunk drivers.

The Court determined there is a difference between blood tests and breath tests for Fourth Amendment purposes.

The Court found that breath tests are non-invasive acts that are akin to blowing air into a balloon.  Also, breath tests provide only one bit of information–the alcohol concentration in a motorist’s blood stream.

However, unlike breath tests, blood tests are more invasive and require more Fourth Amendment protections since they require a needle to be stuck into the arm of a DWI suspect.  Moreover, blood samples convey potentially more information (such as medical illnesses, genetic traits, or other intimate medical data) than just the blood alcohol concentration in the driver’s system.

These distinctions were the difference in these cases.  The Court held that police do not need warrants to obtain breath tests from drunk drivers because they are non-invasive and communicate only the BAC in the driver’s system.  For this reason, warrantless breath tests are permissible  under the search incident to arrest doctrine (SITA).  The Court also found that because warrantless breath test searches are constitutional, then states can prosecute DWI drivers for refusing to submit to breath tests.

The result was different for blood draws.  As noted above, blood draws are more invasive and communicate more information than just the DWI suspect’s BAC.  This justifies requiring police to obtain a search warrant—absent exigent circumstances—before it can draw a DWI driver’s blood.

Further, states cannot criminalize a DWI driver’s refusal to give a blood sample because warrantless blood draws are unconstitutional.  For similar reasons, a DWI driver’s consent to submit to a blood draw under North Dakota’s Implied Consent law is coercive and invalid because the DWI suspect is threatened with criminal prosecution for declining to provide a warrantless blood draw.

The Court then reversed Birchfield’s conviction for refusing to provide a warrantless blood sample since it violated the Fourth Amendment.  But the Court affirmed Bernard’s conviction for not providing a breath sample because the state was allowed to take a breath sample without a warrant.  The Court also said that states can prosecute DWI suspects for refusing to take a breath test because warrantless breath tests are constitutional.

Finally, the Court reversed the judgment against Beylund to determine if Beylund’s consent was still valid in light of the Court’s rulings in this case.

What does this mean for you?

Police are allowed to take warrantless breath specimens from motorists arrested for DWI.  [NOTE—in Texas a person can still decline the breath test].  However, police must get a warrant—absent exigent circumstances—before they take a blood sample from a suspected drunk driver.

Also, on a related topic—people arrested for DWI should listen carefully to the Implied Consent warnings (Tex. Trans. Code 724.011)  given by the arresting officer.  If the warnings are incorrect or coercive, then it’s possible for your defense attorney to move to suppress the results of the breath or blood test.  But this is a very fact specific inquiry.  Talk to your DWI attorney to cover this issue before you decide to plead guilty.

Finally, don’t abandon hope if you are arrested for DWI.  It’s a difficult, embarrassing, and depressing situation to go through.  However, being arrested does not mean you are guilty.  Most importantly, you have rights and remedies if you believe the officer treated you unfairly or arrested you for DWI when you were actually sober.

PHONE:  210-733-7575



The Supreme Court decided an interesting Fourth Amendment issue this morning:

Supreme Court
Supreme Court

What to do when the only way police learn that a suspect has a valid arrest warrant and is in possession of narcotics is by first violating that suspect’s right to be free from an unreasonable search and seizure under the Fourth Amendment.


The fact pattern in Strieff is pretty common.  Police temporarily detain and question a defendant without a valid legal reason—that is, there is no reasonable suspicion or probable cause to stop and question someone, and then during that questioning, discover that the person has an active and unrelated arrest warrant for something minor like unpaid traffic tickets.

Police then arrest that person and search him or her incident to arrest (SITA).  During the search, police find contraband such as pot, coke, meth, or heroin on the arrested person.  The question then becomes—should this evidence be admissible in Court when the only way police learned of the valid pre-existing arrest warrant and narcotics was by illegally detaining the person in the first place.    That’s the issue in Strieff.


In Utah v. Strieff, police saw Edward Strieff leave a suspected-drug house in Salt Lake City, Utah.  However, police had no reasonable suspicion that Strieff committed any offense.  Nevertheless, police detained Strieff, questioned him about his presence at the house, and then learned he had an arrest warrant for an unrelated traffic citation. Police arrested Strieff for the traffic citation and during the search incident to the arrest found methamphetamine and drug paraphernalia on Strieff.

Does a valid arrest warrant attenuate the taint from an illegal and unconstitutional detention?

Strieff was charged with drug possession.  He filed a motion to suppress the drug seizure under the Fourth Amendment, but the trial court denied the motion.  The Utah Supreme Court reversed Strieff’s conviction because it determined that the initial stop violated Strieff’s Fourth Amendment right to be free from an unreasonable search and seizure and that the attenuation doctrine did not cure the initial violation.

The U.S. Supreme Court granted cert. and reversed the Utah Supreme Court.  The U.S. Supreme Court held that the facts in Strieff support allowing the evidence into trial against Strieff under the “attenuation doctrine.”  The attenuation doctrine allows illegally obtained evidence to be admitted under certain facts.  [NOTE:  The Attenuation doctrine has been around for some time–this case is just the latest in a long line of cases applying and clarifying when the doctrine applies.  Thanks to a reader’s comment for this clarification.]

The doctrine directs trial and appellate courts to consider three things before making an attenuation ruling:  (1) temporal proximity between the illegal stop and discovery of evidence; (2) intervening circumstances; and (3) purpose and flagrancy of police misconduct.

A majority of the Supreme Court found that the second and third factors supported applying the “attenuation doctrine” and allowing the illegally obtained evidence to be used against Strieff.  Specifically, the Court characterized the police officer’s conduct as negligent rather than flagrant.  The Court also stated that the valid pre-existing arrest warrant was unrelated and untainted by the officer’s illegal questioning of Strieff.

The Court weighed these factors and determined the arrest warrant for unrelated traffic citations attenuated the taint from the initial illegal detention.  The Court allowed the evidence to be used against Strieff.


This means that you should make sure that you pay all your traffic tickets and clear up active municipal warrants.  Otherwise, police may use the fact of a valid preexisting arrest warrant to excuse their unlawful police conduct and illegally detain or arrest you.

On a side note, if you have an arrest warrant for unpaid traffic fines or tickets with the City of San Antonio, you can contact the municipal court and make arrangements to pay the fine and have the warrant lifted.  Also, people who go to municipal court with active traffic warrants generally are not arrested.  [CAUTION–this is the policy for the City of San Antonio–make sure to check with the municipal court where your ticket is pending before you show up if you have an active warrant.]

PHONE:  210-733-7575