How Accurate is a Drug and Alcohol Test for a DUI?

Author: MatadorAdmin Posted on: . Filed in: Uncategorized.


You will be required to participate in a number of tests if you are stopped by a police officer under suspicion of driving under the influence of drugs or alcohol. Aside from the standard field sobriety test, It is likely that the you will be required to take a breathalyzer and even a blood or urine test. Taking a closer look at the types of tests that may be administered may be helpful as their accuracy often can vary depending on the situation at hand.    


The Most Commonly Used Test

When a person is pulled over for a suspected DUI, law enforcement will likely administer a breathalyzer test at the scene. When you exhale air into a breathalyzer machine, the amount of alcohol you have consumed can be measured to assess the amount of alcohol that is in your system. This test can have inaccuracies as it requires a certain level of guess work because the BAC is an estimation.


False readings could be due to:

  • Rate of respiration
  • Body Temperature
  • When a breathalyzer is not calibrated appropriately before use, the results it gives could be inaccurate.
  • If a person has consumed substances that have alcohol in them such as:
    • Mouthwash
    • Over the counter medications or prescriptions


The Least Accurate Test

When trying to detect drugs or alcohol, a urine test is considered to be the least accurate type of test you can take. Because of this, they are used only when the other types of tests (blood or breathalyzer) are not available. The results can be different depending on the person because bodies metabolize alcohol differently. This is often due to the fact that urine samples are constantly changing the BAC.  


The Most Accurate Test

Not surprisingly, the most accurate type of test for the detection of drugs and alcohol is a blood test. Despite this, there are a number of arguments a DUI attorney may make when looking into the details around the test. Examples of errors include:

  • The proficiency of the person who administered the test
  • The equipment that was used
  • Preservation of the blood samples as when they are not stored properly, the sample could be damaged
  • The record keeping of a lab, an error may occur if they are not well organized and lose track of the samples


Although it is possible for an error to occur when the blood is tested, it is highly unlikely mainly because of how accurate blood testing is.

It is important that you contact a DUI attorney such as the DUI lawyer Peoria IL locals turn to if you have been arrested for a DUI. In the event that a test taken on the scene was inaccurate, they are your best bet for having charges thrown out. An attorney with experience will be able to represent your interests while you endure the legal process.   


Smith & Weer, P.C. Lawyers Thanks to authors at Smith & Weer LLC for their insight into Criminal Defense.


Latest posts by MatadorAdmin (see all)