Reliability of BAC TestsPublished: Jan 03, 2018 in DUI
Law enforcement in Texas can pull you over for a suspected DWI if they have any reason to believe that you are intoxicated behind the wheel. Before they formally arrest you, the police will usually conduct a blood alcohol concentration (BAC) test in order to determine how much alcohol is in your system. BAC tests are often done either on the side of the road or in a police station, and their results will be the primary evidence against you in a DWI case. However, it is very important to understand that these tests are far from perfect, and a flawed test can be unfairly used against you and result in a conviction. To best defend yourself, you need a Houston DWI attorney from The Law Offices of Ned Barnett who has a comprehensive understanding of the various BAC tests.
Attorney Ned Barnett has helped many people successfully fight DWI charges, and he knows how to protect your rights no matter the details of your case. To speak with an experienced DWI defense lawyer in a free, initial case consultation, contact us at (713) 222-6767.
Roadside BAC Tests Can Be Very Unreliable
If you are pulled over on suspected DWI, the officer may have you perform certain physical tests in order to judge if your body is reacting to drugs or alcohol. These roadside field sobriety tests may include a one-leg balance, horizontal gaze, or walk and turn test. However, if it can be shown that you have a BAC of .08 or above, then an arrest will be imminent since you will be determined over the legal limit to drive. A roadside BAC test can make the officer’s job easier since it allows for quick evidence of your intoxication right where you were pulled over.
Breathalyzer readings are the most common form of roadside BAC tests. These devices are often small enough to fit in an officer’s pocket, and they analyze a sample of your breath in order to calculate what amount of alcohol may be in your blood. As a Houston DWI lawyer with years of experience, Ned Barnett has seen many cases where the prosecution tries to use unreliable breathalyzer results to prosecution someone. A defense against your breathalyzer reading may include one of the following flaws of these devices:
- Outside, environmental substances were not properly kept out of your breath test, and these can result in a false reading. These substances include medicine, mints, and certain foods can make breathalyzers inaccurate.
- The arresting officer did not monitor you for enough time before administering the test. This is done to make sure that you do not ingest something that could alter the test, and to ensure that you do not burp or vomit, therefore introducing food or drink particles into your mouth.
- The breath device was not properly calibrated. These machines must be maintained so that they can properly read a person’s breath and return consistent results.
Tests Performed at the Police Station are Subject to Flaws as Well
The most convincing of the BAC tests would be a reading of a blood sample using a machine such as a Gas Chromatograph. If done properly, these tests are widely considered to be extremely accurate in determining how much alcohol is in a blood sample. However, officers or lab technicians often make mistakes while using these machines, and these mistakes can result in inaccurate results that are used in your DWI case.
If you are facing an incriminating BAC test performed by a blood-reading device, your lawyer will must understand how to make sure that this test was performed properly, and how to fight its reading if it was not. Of the many ways we have seen blood sample BAC tests invalidated include:
- The blood was improperly drawn and therefore tainted by outside substances
- The blood was improperly stored after being drawn and before being tested
- The machine was not properly calibrated and maintained
- The lab or company performing the test was unforthcoming about its practices, even after being found to have made many BAC test mistakes
- Samples or results were switched and assigned to the wrong defendant
The Law Offices of Ned Barnett Can Help You
BAC tests can help officers determine if a person is intoxicated, and they are often used to convict someone of a DWI. However, many people such as police and prosecutors would like to consider these tests to be perfect, but we know that they are far from flawless and are often conducted erroneously. If you or a loved one have been arrested due to the result of a BAC test, you will need a skilled and understanding lawyer to take your case.