Blood and Breath Testing in WI Traffic Cases

A Madison Defense Attorney on Challenging BAC and Probable Cause

There are a number of commonly held misconceptions surrounding the testing of an individual's breath or blood by law enforcement pursuant to a traffic stop. Knowing the distinctions and your rights within each area could have drastic effects on the defense of your case and on your future.

Breathalyzer Testing

Not to be confused with an Intoximeter, a Breathalyzer or PBT (preliminary breath test) is a hand-held device, roughly the size of a deck of playing cards, into which a police officer may insert a tube and ask you to "blow." This will probably happen either roadside or somewhere fairly near to where you were stopped. It's important to understand that this is a field test, which may be requested of you — along with some other standard field sobriety tests (FSTs). FSTs would likely include the walk-and-turn, the one-legged stand and the horizontal gaze nystagmus tests.

Unlike the FSTs, courts have determined that the results of a PBT/Breathalyzer are not reliable enough as evidence of impairment to submit to a jury in a trial for drunk driving. However, the results of both the PBT and FSTs absolutely may be relied upon, along with other observations, by a police officer in determining whether he/she has probable cause to arrest you.

It is lawful to decline to perform either or both the FSTs and the PBT/Breathalyzer. This will not, in and of itself, provide a basis for any additional citation. Declining to perform the PBT and FSTs would also obviously deprive the officer of any evidence of impairment gathered through those means. However, you must be aware that your refusal to comply with field testing is, by itself, considered evidence supportive of probable cause to arrest. So the decision to decline may well earn you an arrest and a ride in a police car.

Officers are trained to note their observations of your driving, appearance, speech, behavior and any FSTs/PBT results. If after seeing all of this, they feel they have probable cause to believe you were operating while impaired, they will likely ask you to provide a sample of either your blood (at a hospital) or your breath (at the police station). Unlike the PBT results, the results of these forms of testing may be submitted to a jury.

Blood Testing

The U.S. Supreme Court recently held that if a person refuses to provide a blood sample, the police must obtain a warrant for the blood draw — signed by a judge. However, absent some previously diagnosed medical condition, such as hemophilia, this is not advisable. There are two reasons this is a bad idea. First, unless you are being arrested for a first offense, the police likely will get the warrant for a forcible blood draw anyway — in which case you won't really have achieved anything. It usually isn't very difficult for them to reach a judge, even late at night.

Second, refusal to provide a legally admissible sample (again, not to be confused with the PBT/Breathalyzer) of your blood or breath upon request by law enforcement will usually result in a "refusal" citation. This is also known as a violation of the implied consent law. A refusal citation is to be avoided if at all possible because it is, in some ways, more difficult to defend against than an OWI/DUI. To convict you of a refusal, it isn't necessary to prove that you were, in fact, driving while impaired or under the influence — only that an officer lawfully made the request, and you refused.

Further, a refusal conviction carries some of the same penalties (in some cases, an even lengthier driver's license revocation) and would essentially count as a prior OWI for purposes of escalating the penalties in the event you are ever again charged with OWI. It does not feature jail time as a potential penalty but, as noted previously, unless it is your first offense, the officer will likely get a warrant for your blood (to support an OWI charge) regardless. So you may only be piling the refusal atop an OWI.

Bottom line: Don't refuse the needle if it is requested of you. It will only make your situation worse and more difficult to defend.

Intoximeter Testing

An Intoximeter (also known as an Intoxilyzer) is a breath-testing device (larger than the PBT) you would typically encounter at the police station after the officer has already made the decision to arrest you. Before testing, an officer will watch you for 20 minutes to ensure that you don't vomit or consume anything as these issues could throw off the test. For some models, a breathing mask is strapped to your head. You will typically breathe into this device for a longer period of time than what is required for the PBT.

Whereas the PBT is a field test used to screen for prior alcohol consumption, to develop probable cause to arrest, the results of an appropriately administered Intoximeter test may be shown to a jury as evidence of your blood alcohol content (BAC). This form of test may be done in lieu of a blood draw and essentially triggers all of the same legal considerations.

Therefore, if you refuse to provide a sample of your breath upon request for Intoximeter analysis, it will typically result in a refusal citation just as with a blood draw. It may also lead to a forced blood draw in that event.

Bottom line: Recognize the difference between an Intoximeter/Intoxilyzer and a Breathalyzer/PBT. They aren't the same thing. As with a needle (blood draw), never refuse to provide a sample of your breath if requested for Intoximeter testing at a police station.

Incidentally: If you have concerns about Intoximeter testing at the time you are arrested, you may request a blood draw in addition to the Intoximeter test. Note, however, that while the officer would be required to transport you for the blood draw, you are not then entitled to refuse the Intoximeter test if you make that request. In other words, you can request an additional test, but you do not essentially get to pick your form of testing.

A Final Note

If you are stopped and provide a sample of your blood or breath indicating a BAC result over .08 percent, all is not necessarily lost. Various other factors may affect whether (or how) those results would be presented to a jury. Such factors include:

  • Delay between driving and testing
  • Whether any alcohol was consumed between driving and testing
  • Whether the individual has any health conditions that may affect the test (such as gastroesophageal reflux disease, or GERD)
  • Whether the machine was properly calibrated
  • Whether the machine operator was properly trained
  • Chain of custody
  • Circumstances that might support a "curve" defense
  • Whether there was probable cause to arrest

Contact a Lawyer Dedicated to Protecting Your Interests

If you have been accused of driving under the influence, it is important to seek qualified legal advice as soon as possible.

At Frederick Law Office, my promise as a Wisconsin criminal defense attorney is to help you achieve the best possible outcome in your DUI/OWI case. With more than a decade of experience, I understand how to attack the evidence in an effort to get your charges reduced or dismissed. I know how to challenge the results of breath and blood testing as part of a comprehensive drunk driving (or drugged driving) defense. When you meet with me, we will discuss all potential options and determine the best path forward.

Contact me online or call my Madison law office at 608-258-8529. There is no charge for the initial consultation.