A DUI can have a long-term negative effect on your life, from its impact on your driving record to the potential to lose your license and more. However, many people who have participated in sobriety tests when being pulled over for a potential DUI believe that because their sobriety test came back positive for drugs or alcohol, they have no further recourse. In reality, this is not true.
Before you admit to a DUI conviction without contest, be sure you understand the various types of sobriety tests administered by law enforcement, including field sobriety tests, breathalyzer tests, and blood tests.
Knowing how the results of these tests can influence the outcome of a DUI case — from initial arrest to courtroom proceedings — gives you the power to defend your rights or mitigate charges or sentences where possible with the help of a legal team.
Understanding Sobriety Testing
Sobriety testing is an umbrella expression under which multiple types of tests exist. The most commonly used are field sobriety tests and breathalyzer tests. However, more officers than ever are now undergoing blood draw training so they can conduct on-site blood tests as well.
Field Sobriety Tests
When a person is pulled over for a potential DUI, the officer may request that they exit their vehicle and perform three controlled physical tests: the HGN (Horizontal Gaze Nystagmus) test, walk & turn test, and one-leg stand test.
- HGN Test – The HGN test, or horizontal gaze nystagmus test, looks at the eyes to see whether they jerk when looking side to side. Individuals under the influence of alcohol or drugs typically exhibit increased jerking movement of the eyes due to substance impairment.
- Walk & Turn Test – The officer asks the suspect to walk nine steps from heel to toe, then turn around and repeat in a straight line. People who lose their balance or struggle to complete this task using the specified directions are deemed more likely to be intoxicated.
- One-Leg Stand Test – The suspect must stand on one leg, raise the other leg at least six inches above the standing foot, and hold the position for 30 seconds. This test checks a person’s balance, which can become impaired when intoxicated.
Breathalyzer Tests
A driver may be asked to breathe into a machine using a continuous, deep breath. The machine measures how much alcohol the exhaled air contains and can indicate whether there is any alcohol in your system.
Blood Tests
Drivers may be subjected to a blood test, which can identify the blood alcohol content suspended in the bloodstream. This is considered to be the most accurate form of intoxication testing. Some blood tests can also identify the presence of certain drugs.
How Sobriety Tests Factor into DUI Cases
Most drivers wonder what role their sobriety tests play in a potential conviction. The reality is that a judge will often consider a failed sobriety test as a strong factor in favor of conviction, but an experienced legal team find the grounds to contest the results, to have them deemed inadmissible as evidence. Field sobriety tests can be inaccurate, and there are many possibilities for why a failure occurred.
Challenging Sobriety Tests
Each type of sobriety test can be challenged, but some are more likely to be inadmissible than others.
- Field Sobriety Tests – Studies have repeatedly shown as far back as 1977 and as recently as 2023 that the standard field sobriety tests have a high false positive rate — potentially in excess of 20%. A person may fail to pass these tests for many reasons, from injuries or innately poor balance to misunderstanding the officer’s instructions or being nervous. Attorneys can challenge field sobriety tests on these grounds, as well as whether the tests were administered properly, whether the officer has the correct training, and whether the driver’s constitutional rights were respected.
Breathalyzer Tests – Breathalyzer machines must be calibrated to function properly, and it is possible for a sober individual to fail an improperly calibrated breathalyzer — especially the portable machines police officers carry. Studies testing multiple models showed false failure rates as high as one in four.- Blood Tests – In order for the results of a blood test to be admissible in court, the test must be administered properly. This includes proper transportation and chain of custody, a sufficient amount of blood drawn, and mixing the blood with the vial contents properly. Attorneys can challenge these and many other steps of the process.
Get DUI Help from The Law Office of Kermit Monge
If you are facing a DUI charge with a failed sobriety test, you may not be convicted of DUI. The attorneys at The Law Offices of Kermit A. Monge can help you demonstrate the best possible case and mitigate the consequences where possible based on test errors, demonstrations of the unreliability of tests, and more. Contact Kermit A. Monge to schedule a consultation.