Should I Take a Breath Test?

This is one of the most commonly-asked questions in DUI defense, and also one of the most difficult ones to answer. On the one hand, it is generally best to stop digging if one falls into a hole. Refusing a breath test will not improve the situation and may, in fact, make things worse. On the other hand, the conviction rate is almost twice as high in test cases as it is in non-test cases, and since prosecutors already have plenty of tools to convict defendants, it makes little sense to give them more ammunition.

Because of the legitimate arguments for both “yes” and “no,” anyone who gives such an answer to the above question is probably inexperienced in DUI law. What is behind the numbers, and why is there such a discrepancy in the conviction rates for basically the same offense? The answer lies in the evidence.

Circumstantial Evidence

Illinois is an implied-consent state, which means that drivers consent to provide chemical samples to officers when they sign their driver’s licenses. However, defendants also have a Fifth Amendment right not to testify against themselves by making either verbal or nonverbal statements, and that right effectively trumps the implied-consent law.

If defendants refuse to blow into a breath-test machine or allow a doctor to draw blood, the prosecutor must rely on the SFST (Standardized Field Sobriety Test) battery. These three tests are about 80% accurate in determining intoxication, if they are conducted under controlled conditions. However, adverse environmental effects often skew the results.

  • One Leg Stand: It is difficult to stand on one leg for thirty seconds in a quiet room where there is plenty of light and no distractions, and it is even more difficult to do so in the dark of night, on a possibly uneven surface, as emergency lights flash and cars zoom past.
  • Walk-and-Turn: In both the OLS and WAT, officers often assign failing grades based on hyper-technical flaws, such as starting with the wrong foot, starting before the officers say “go,” taking the incorrect number of steps, or barely-noticeable sways while walking heel to toe.
  • Horizontal Gaze Nystagmus: In addition to the darkness and flashing lights, there are many other causes for nystagmus, which is an involuntary eye movement that happens when subjects track moving objects with only their eyes.

Unapproved field tests, such as reciting the ABCs, either may not be admissible at all or may only be allowed for limited purposes.

Direct Evidence

Nearly all test cases involve breath tests because, although blood draws are more accurate, they require search warrants. Some common breath test flaws include:

  • Calibration: Today’s devices are more sophisticated and therefore more difficult to operate and maintain.
  • Mouth Alcohol: Officers must carefully watch defendants for at least fifteen minutes before the test to ensure they do not burp, vomit, or belch, because the resulting mouth alcohol shows up as blood alcohol.
  • Acetone: Smokers and diabetics have greatly elevate acetone levels in their blood, and the Intoxilyzer often falsely registered this substance as ethanol.

These flaws, and others like them, are normally sufficient to convince a jury that the results may be off by about .01 or .02, which can be the difference between a guilty and not-guilty verdict.

Contact Aggressive Attorneys

At Glasgow & Olsson, we are committed to the best possible result under the circumstances. Contact us today for a free consultation with an experienced criminal defense lawyer in Schaumburg. Home and jail visits are available.

(image courtesy of Rsheram)

This entry was posted in: 

And tagged: