Challenging DUI Blood Tests

If ever pulled over at a checkpoint or pulled over for suspicion of a DUI, know the police can request you take a breathalyzer test to test your BAC (blood alcohol content). But did you know there are also two other types of tests law enforcement can order to determine if you have driven under the influence? In addition to a breathalyzer (or breath test), it is legal for an officer to ask for a urine test or blood test. 


When you received your driver’s license, you agreed to an implied consent law, which requires all drivers who are lawfully arrested for driving under the influence to submit to a chemical test, which includes a blood test.  


Our DUI attorneys at Stechschulte Nell Law want you to know if you ever find yourself in a situation where you were asked for a blood test, it is important to know how blood testing works and how there are some possible defense challenges to them. 



If arrested, have a board-certified attorney on your side. Contact us 24/7 to discuss your unique case and legal options. 


How are Blood Tests Performed? 


When an officer arrests a suspect for DUI, they will generally conduct a chemical test to determine the amount of alcohol or drugs in the suspect’s system. Unlike a breathalyzer, a blood test is a medical procedure that cannot be conducted by a police officer.  


The officer will need to transport the suspect to a medical facility or location where a qualified person, such as a phlebotomist, can draw the blood.  


The results of a blood test are not instantaneous and can  

take several days or weeks to get the results back.  


Although the results take longer than a breathalyzer that is immediate, the results of a blood test are more accurate and can also show the presence of drugs and alcohol in the suspect’s system.  



Common Defense to DUI Blood Test #1: Reliability 


Blood tests are generally more reliable than breath tests, but there are some exceptions to their reliability.  


The first exception is when the test is not properly handled or preserved. If they are not properly handled or preserved, they can be contaminated and no longer are an accurate measure of the suspect’s BAC level. This can be a mix-up with the labeling, delivery, or handling of the blood. The blood could also be stored improperly or not adequately mixed with the proper preservatives and anticoagulants which may lead to fermented blood, which results in a higher reading.  


Additionally, Florida law specifies that the washing of the blood draw spot cannot contain alcohol. If anyone of these issues happened, it will result in faulty readings and unreliability.  


The second exception to blood test reliability is the delay from when the suspect was driving to when the blood test was conducted. Contrary to popular belief, the longer the delay between the two, the higher the BAC will be. A person’s BAC level is always changing, and if the suspect continued to drink right until they drove, and then was tested with a delay from being pulled over their BAC will be higher than it was when they were driving.  


This is called the “rising-blood-alcohol” defense. This defense simply states that the BAC was below the limit when the defendant was driving, but above the legal limit at the time of the blood draw. 



Learn More > How to Contest a Florida DUI 



Common Defense to DUI Blood Test #2: Illegal Search and Seizure 


The second most common defense against DUI blood tests is an illegal search and seizure. The Fourth Amendment of the U.S. Constitution protects against illegal search and seizures, which means for a search and seizure to happen there needs to be a warrant or it violates the constitution and is not valid in court. 


A DUI blood draw is within the search-and-seizure constitution protections of the Fourth Amendment and requires the police to either get a warrant or a suspect’s consent to lawfully draw the blood.  


There are some exceptions to this though, the most common is if the suspect is unconscious. 


If there is a case of illegal search and seizure of the DUI blood test, the defense will challenge the court and try to get the results of the blood test thrown out, which means there is a good chance the charges will be dismissed without having any proof of BAC levels. 



Get Help from a DUI Attorney 


DUI law is complicated, especially when blood tests are conducted. If you have ever been arrested for a DUI and given a blood test, you need to reach out to an experienced and knowledgeable DUI attorney at Stechschulte Nell Law.  


Our attorneys will evaluate your case, look through the evidence, and see what defenses we can use to help you fight your charges. Call today for a free consultation at (813) 280-1244. 


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