If you’ve been arrested for a DUI, it helps to understand the case against you. Law enforcement will typically assess your sobriety using a chemical blood alcohol concentration (BAC) test. Although these tests are often used as evidence in court, they aren’t always 100 percent accurate. BAC tests are not to be confused with highly inaccurate field sobriety tests, which look at physical “tells” like your stability and coordination. BAC tests, on the other hand, use a scientific analysis of bodily chemicals to measure the levels of alcohol in your blood. Take a look at these common forms of BAC testing and their relative accuracy.
Saliva testing can be used to determine BAC, but the results can vary, and its uses are situational. Because the common methods for saliva testing take only a few minutes to produce results, and because of their straightforward and non-invasive nature, the tests can be administered on-site. Some studies have found that saliva testing may be more helpful for clinical purposes—like the diagnosis and treatment of trauma patients—as opposed to criminal cases.
Research has found that hair follicles may contain remnants of alcohol, especially in cases of sustained alcohol abuse. Traces of alcohol abuse can last 3 to 6 months in hair from the time of the incident. With some hair testing methods, the results can be skewed by hair washing and products like gel, hairspray, and dye. While some methods are more sensitive than others (and more indicative of alcohol abuse), hair follicle testing is still too inaccurate for criminal cases.
Urine tests are generally only used when breath and blood tests are not available as options, or when people need proof of abstinence for an employer or law enforcement official. Urine testing isn’t ideal in a criminal case. Besides the fact that urine tests are difficult to perform on the road, alcohol levels take up to two hours to appear in a person’s urine and remain in the body for 6 to 24 hours. For that reason, a positive urine test may not prove that a person was under the influence when the traffic incident occurred. What’s more, it’s easy to tamper with urine samples and pass them off as genuine. Even the most accurate urine testing methods can be thrown off by the use of certain products, foods, and medications.
This is the most common test. Unlike urine and blood tests, breath analysis is considered non-invasive. It’s the most accurate method of BAC measurement besides the blood test, but still has substantial margin of error. That means if you register .08 on this test, your actual BAC may be below this level. Different machines (or “breathalyzers”) use different methods to test blood alcohol levels, but the most current method analyzes exhaled vapor to find alcohol content using a method called infrared spectroscopic analysis. Although breathalyzers are generally accepted by the courts, independent studies have shown that breath readings can vary by 15 percent when compared to blood test results (which offer the closest thing to “actual” BAC levels).
Because blood tests involve an invasive procedure, they are used less often than breath analysis. They are mainly used after serious accidents or incidents where a suspect refused the breathalyzer test. Blood screening is the most accurate form of BAC testing and, therefore, typically the most trusted in a court of law. However, even these tests are only admissible if properly conducted by the right personnel. For example, in many cases, blood tests conducted by a hospital, as opposed to the Georgia Bureau of Investigation’s forensic laboratory, will NOT be admissible in a criminal case.
If you have been arrested for DUI, the first thing you should do is contact a qualified DUI lawyer. Savannah DUI can determine the best course of action to defend against your charges and minimize the consequences. Give us a call and let us help you like we have helped so many others.