Challenging DUI Blood Test Results

When you get your Illinois driver’s license, you automatically consent to chemical testing if the police suspect that you’re driving while intoxicated. Chemical testing means providing a sample of your blood, breath, or urine. Out of all of these tests, blood tests are the most popular in DUI cases because of their high levels of accuracy in pinpointing your blood alcohol content (BAC).

However, even blood tests are not error-proof, and they can provide false positives from time to time. Blood testing is a scientific process and requires strict procedure. Any deviation from the procedures can make the results of your blood test inadmissible as evidence of your drunk driving. That’s why you need to contact a Chicago DUI lawyer right away if you submitted to blood testing for a DUI.

Call O’Meara Law today at 312-909-0706.

Is Blood Testing Reliable?

Of the three chemical tests performed on people accused of a DUI charge, blood tests tend to be the most reliable. That’s because DUIs are based on blood alcohol content (BAC), so it follows that the best way to get accurate results would be to test your blood. However, the test’s supposed accuracy is based on the presumption that the person giving the test follows proper procedures, that your blood sample is properly handled, and that it doesn’t get mixed up with that of another suspect.

For this reason, criminal courts must exclude blood tests that do not meet the stringent requirements that ensure their accuracy. Your lawyer can ask the judge handling your case to suppress your blood test results if there is evidence that the police or the medical professionals administering the test failed to follow procedure to the letter.

Challenging a Blood Test

A blood test can be successfully challenged in several ways, including the following:

  • The person was unqualified to draw your blood. A trained medical professional must draw your blood and send it to the lab. Your lawyer will investigate who took your blood sample. If that person was not qualified, your blood test result may be thrown out of court.
  • Labeling errors caused confusion. By carefully reviewing all the evidence pertaining to your blood test, your lawyer may discover that your sample was improperly labeled. The vial may have your name on it, but a time and date inconsistent with the timeline of your arrest. This could mean that your name got written on someone else’s sample. In such cases, the blood test result should be excluded from the case.
  • Storage issues resulted in errors. Improper storage and delays in the storage of your blood sample can result in elevated error rates. That’s because the yeast, sugar, and bacteria in your blood can cause fermentation, which can significantly skew the results. Alcohol is created during the fermentation process, so if your BAC was low when the blood was drawn, it will be much higher when the sample was analyzed. Your lawyer will question the lab technicians and review the paper trail that could show your sample was poorly stored.
  • Errors in testing resulted in inaccurate results. Sometimes the machines used to test your blood are not working properly. They often need to be calibrated, just like breathalyzers. Your lawyer will discover whether the lab equipment was regularly maintained. If not, there is no way to be sure the equipment didn’t give a false report of your elevated BAC.
  • Tampering occurred with the sample. Only certain people are to have possession and control of your blood sample at any given time. There is a chain of custody in place to prevent tampering. If the record shows that the chain of custody was broken, the sample may be considered tampered with, and the judge may suppress it.

Getting Legal Help

When a blood test is performed correctly, it will accurately report your BAC. The problem is that the police, medical professionals, and lab technicians often make mistakes. It’s up to you and your Chicago DUI lawyer to discover these mistakes and report them to the judge presiding over your case. The prosecutor is certainly not going to review whether your sample was properly collected, labeled, and stored before charging you with DUI. For this reason, you should hire an experienced Chicago criminal defense lawyer to review your case as soon as possible.

Your blood test results can be challenged, and it can make a significant difference in the outcome of your DUI case. At O’Meara Law, we’ve helped countless individuals avoid a DUI conviction by quickly reviewing their case file and highlighting issues with the BAC tests being used as evidence.

To find out if your blood test results can be removed from your case, call us today at 312-909-0706 for a free and confidential consultation.