What Happens if I Fail a Breathalyzer Test?

DUI & DWAI – Why Failing the Roadside and Breath/Blood Tests is Not the End of your Case

If you have been charged with DUI or DWAI, you likely failed the roadside test and the breath/blood test.  Because of this, you may think that your case is over.  After all, the jury is going to believe the officer’s testimony about how badly you did on your roadside test, right?  Surely, they will believe the officer even more when the breath/blood test confirm what the officer saw.

Actually, you may be surprised.

To be sure, the jury will consider the officer’s testimony and the test results.  Indeed, they must.  But what is often critically important to a DUI or DWAI case is not just your blood alcohol content (BAC) or what the officer says on the stand.  Instead, what often makes the difference in a DUI/DWAI case is what was not said.  And this is where cross-examination of the officer becomes vital.

How Did You Perform on the Dozens of Roadside Tests You Didn’t Even Know About?

While there is one official roadside test (comprised on many smaller tests), the truth is, there are dozens of “roadside tests” that you took without even knowing it.  For example, when the officer was behind you and turned on the patrol car’s overhead lights, did you slam on the brakes or, instead, did you pull over at the nearest safe location without incident?  When the officer asked you for your license and registration, did you open the ash tray and look for them, or did you open your wallet and glove box and hand the officer the requested items?  When the officer asked you to step out of the car, did you plant face first into the ground, or did you unbuckle your seat belt, open the door, and step out of the car easily?

How do these things matter?  And more importantly, how do they matter when you had a high BAC result?  Because of the law.

Colorado DUI Law

The primary DUI law in Colorado states that “[i]f … the defendant’s BAC was in excess of 0.05 but less than 0.08, such facts give rise to a permissible inference that the defendant’s ability to operate a motor vehicle was impaired.”[1]  Likewise, if your BAC is 0.08 or above, “such facts give rise to the permissible inference that the defendant was under the influence of alcohol.”[2]  Importantly though, nothing in this language “shall be construed as limiting the . . . consideration [by the jury] of any other competent evidence bearing on the question of whether or not the defendant was under the influence of alcohol or whether or not the defendant’s ability to operate a motor vehicle was impaired by the consumption of alcohol.”[3]

What does all that mean?  Put simply, it means that if your BAC was above 0.05, the jury members are permitted to infer you were DUI or DWAI, but they do not have to.  Instead, by law, the jury can draw the opposite inference.  This means the jury can look at a bad “official” roadside test and even a BAC of .08 and above and find you not guilty DUI or DWAI.


By looking at the other evidence admitted.  Remember all those unofficial roadside tests – the ones you took and passed with flying colors without even knowing it?  That evidence.  Evidence which showed you were properly and safely controlling your vehicle.  In short, evidence you were not impaired.

Getting Favorable Evidence Admitted

But how do you get that evidence admitted?  One way is cross-examination of the officer.  And if the officer is forced to admit – to the jury – that you responded properly to the patrol car’s overhead lights, pulled over safely, handed him or her the correct paperwork, got out of the vehicle without any trouble, or passed any number of other tests which can be brought out during cross-examination, then the officer is now telling the jury that you were coordinated and in control.   In effect, the officer is now testifying on your behalf.  And that is the opposite of what the prosecutor needs for a conviction.

So, even if you had a bad roadside test or high BAC, don’t give up because the fight is not over yet.  Remember – you are legally innocent.  Find a good attorney – and make the government prove its case.

If you’ve been charged with DUI, or any crime, your best option is to immediately retain a criminal defense attorney who can begin gathering the facts needed to support your case.  I invite you to call me to learn how my firm can help. Consultations with my firm are always free.


[1] C.R.S. 42-4-1301(6)(a)(II).

[2] C.R.S. 42-4-1301(6)(a)(III).

[3] C.R.S. 42-4-1301(6)(b); see also C.R.S. 42-4-1301(2)(b).

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