A person who takes a breath or chemical test and is charged with driving under the influence in Chicago may not automatically face the severe penalties that go along with the conviction. In fact, this should never be a foregone conclusion. According to the National District Attorneys Association, there are many DUI defense strategies that may be effective in court.

When it comes to a breath analyzer device, many factors could cause a false reading. Diabetes and gastrointestinal reflux disease are two medical conditions that could indicate a high blood alcohol content, even if a person has not been drinking much, or at all. Problems with the device such as improper calibration may also cause a false readout.

There are many ways to challenge the results of a blood draw, as well. For example, if the laboratory technician collects blood in tubes that have expired, or does not package and store the blood correctly, the accuracy of the test may be compromised. The person who collects the sample may use a swab that contains alcohol, which could contaminate the blood. To reach any of these conclusions, scientific knowledge is often needed to analyze the circumstances.

According to Forensic Magazine, an expert witness may tip the balance toward the defendant in a DUI case. This professional should be able and willing to conduct the necessary tests and discuss the results with both the prosecution and the defense before going to court and taking the witness stand. With unbiased scientific evidence at hand, there may not be a need for the case to proceed, but if it goes to trial, the judge and jury often respond positively to clear statements of facts.