Updated on January 12th, 2024 at 04:16 pm

Wisconsin DUI Chemical Testing to Determine BAC

The most essential element of the state’s case against you is the results of your chemical test to determine your blood alcohol concentration. Traditionally, there are three different evidentiary chemical tests in Wisconsin: blood, breath, or urine.  When an officer arrests you for DUI / OWI, they will ask you to submit to an evidentiary test, typically it will be either a blood or breath test. The results of these tests then provide the proof the city or state needs to charge you with DUI/DWI/OWI.

Chemical Test Results are not Bulletproof! Attack Them!

The admissibility of chemical test results as evidence depends on whether the tests were administered according to proper standards and guidelines. This is a question that an experienced Milwaukee DUI attorney will be able to answer.

If you are given a breath test, the results are admissible only if the officer administering the test was properly qualified, the test was conducted according to proper procedure, and the EC/IR II Breath Test Machine used for testing were accurate as well as calibrated, maintained, and repaired properly with records to prove it.

For Blood Testing, the same standards as for breathalyzers apply, with some added caveats: the laboratory qualifications and certifications as well as those of the technicians, the chain of custody of the sample, and the reporting procedures for the results must be examined.

There are many errors that could be made in the case of such tests, including but not limited to:

   1.)  Testing procedures were faulty;
   2.)  Lack of adequate training on the part of the technician;
   3.)  Lack of proper inspections of the facility;
   4.)  Disregard or negligence of regulations on sample handling.

Specifically in the case of a blood test, contamination is possible if the puncture site was cleaned with an alcohol swab prior to the blood being taken, which invalidates the evidence. With urinalysis, your Milwaukee DUI attorney can investigate the accuracy and reliability of such test results.

Refusing To Submit to a Blood or Breath Tests can have a significant impact on your case and on any potential penalties you face.  Though the state would be without test results as evidence, the refusal itself can be used as evidence against you by the state. Your Milwaukee DUI lawyer might be able to show that your refusal was not actually a refusal and simply reflected your desire to seek counsel before submitting.

A qualified Milwaukee DUI attorney will be able to examine all of the evidence, even the seemingly objective results of chemical tests, and see if there is anything there that can be contested or whose validity can be questioned. Contact a Milwaukee DUI lawyer at Vanden Heuvel & Dineen, S.C. by filling out the form on the page to find out what you can do to fight a DUI charge.