Free Consultations | Available 24 / 7

Call Us262-232-6699

711 W. Moreland Blvd. Suite 205
Waukesha, WI 53188

How does a Breathalyzer test device work?

Posted on in OWI

If you were arrested for drunk driving, at some point during your arrest process, police probably administered a Breathalyzer test. The results of this test may have even produced a key piece of evidence in your criminal defense lawsuit, and the prosecution may try to use this evidence against you to convict you of drunk driving. As such, you might want to understand a little more about how Breathalyzer tests work.

The Breathalyzer test machine comes in numerous forms and variety. "Breathalyzer" is a brand name, but other companies may offer breath testing devices as well. Generally, all of these devices work the same, and they are all subject to rending completely inaccurate test results. As such, even if your breath test showed you had a high blood alcohol content (BAC), it doesn't necessarily mean that you will ultimately be convicted.

Breathalyzers analyze the percentage concentration of alcohol in your blood by registering how much alcohol is dissolved into your breath. A scientific testing methodology known as infrared spectroscopic analysis is used to analyze your breath like this. The captured alcohol within your breath is detected because it absorbs light waves that belong to a specific frequency. The more of these lightwaves the are captured, the higher score of drunkenness the Breathalyzer will give you.


How do lawyers defend against drunk driving?

Posted on in OWI

It might have happened while you were driving home from a party late at night. It might have happened while you were driving your children to school in the morning. In fact, a drunk driving arrest can happen at any time you're operating your vehicle. However, just because you get arrested and accused of this crime does not mean that a criminal court will find you guilty. Until the prosecution can prove you were drunk behind the wheel beyond a reasonable doubt, you will have every opportunity to defend yourself.

Although every drunk driving defense strategy will be different depending on the circumstances of how the arrest occurred, here are a two ways that DUI defendants might try to fight their charges:

Defenses related to police procedure: There are many things that can go wrong in the moments preceding a driver's arrest. Police have rules and procedures they need to follow, and failure to follow these rules could invalidate an arrest. Important questions to ask in this regard include: Did the police have a viable reason to pull over the driver? Did police administer the field sobriety or breathalyzer test in a lawful way? If the answer to these questions is "no," then it could reveal a strategy to defend against the charges.


The law in Wisconsin is exceedingly clear. Individuals who have a blood alcohol content beyond .08 percent cannot legally operate an automobile on the road. In fact, they can't even sit in the driver's seat while drunk with the vehicle pulled over on the side of the road without running the risk of getting arrested for a DUI. All that said, many drivers are surprised to hear that there are certain exceedingly rare circumstances in which it is actually legal to driver while intoxicated.

Before we discuss some examples of these circumstances -- when it's legal to drive drunk -- readers should be warned: This is not something to do on purpose, and it only applies to rare and emergency situations.

Here are two situations in which a driver could theoretically drive drunk and get away with it:


How do police determine if a driver is drunk?

Posted on in OWI

Police use a variety of methodologies to spot potentially drunk drivers. Learning what police look for might help you avoid an inappropriate DUI. In fact, many drivers in Wisconsin have been arrested and charged with DUI because they made some simple and relatively harmless mistake on the road. If you're sober, and you know what to avoid, it should be fairly easy to prevent making the following errors by mistake:

  • Driving in an unpredictable and or erratic way: Drivers who are intoxicated tend to operate their vehicles erratically. They might cross the centerline suddenly without warning. They might speed up and slow down for no reason at all. They could be piloting their vehicles in other strange ways that call attention to the vehicle and driver. As long as you're driving close to the speed limit, and you're maintaining your speed and your lane in a steady way, you should be able to avoid the risk of getting falsely accused of a DUI.
  • Being overly nervous during a field sobriety test: Stay calm and respectful during your field sobriety test, and remember to breathe. It's easy to get nervous when police are administering a field sobriety test. However, that nervousness -- if it's extreme enough -- could cause police to think you're intoxicated, so be sure to stay as calm as you can.
  • Failing to pass your Breathalyzer test: No sober driver should ever fail a Breathalyzer test, but it does happen from time to time. Ultimately, there's nothing you can do to pass or fail this test. Just blow if you haven't been drinking, your test results should reflect that. If you aren't intoxicated, but the breath test shows that you are, you might be able to challenge the accuracy of test results in court at a later time.

Being falsely accused of drunk driving is not the end of the world. You will have the right to defend yourself against the charges in court; and, if you're innocent of the charges, the prosecution should not be able to convict you of a crime you didn't commit.

Source: FindLaw, "DUI Traffic Stop FAQ," accessed Jan. 05, 2018

If you recently received DUI charges, it can feel as though you have no way to fight them. The truth is that there is usually something a very creative person can find to build some sort of defense. While there is no guarantee that the defense succeeds in preventing a conviction, it is always better to build some sort of defense against any kind of criminal charge.

Without a legal defense of some kind, the prosecutor handling your case has nothing to prevent them from throwing the book at you and using you as an example to other alleged offenders. Even if the officer who arrested you administered a breathalyzer test and it indicated that you were over the limit, you may still have more options than you think you do.

In most cases, it is most effective to enlist the help of an experienced DUI defense attorney. Such an attorney fully understands the laws that govern DUI stops and arrests, as well as the local justice system and the major players in it. With proper legal counsel from an experienced, established defense attorney, you can confidently fight for fair treatment while protecting your rights.

NTL BBB Best DUI Lawyers in Milwaukee EDWBA WACDL Commerce WCBA SBW
Back to Top