There are three standard tests that the state can utilize to determine if a DUI suspect has been drinking and driving: the urine test, blood test, and breath test. These are called chemical tests because, unlike field sobriety tests, they take a sample of something that comes from the suspect’s body to test for the presence and amount of alcohol in his system. Each test serves a purpose despite them all being used to detect one thing: a blood alcohol concentration of 0.08 or above. Each test is also susceptible to flaws that produce inaccurate results.
The chemical breath test is the most commonly used method to measure a suspect’s BAC. In Florida, it is conducted using the Intoxilyzer 8000. This test is not considered an invasive method as it measures deep lung air, or the air in the alveoli sacs. The alcohol content of this air is thought to most closely correlate with the blood.
To conduct this test, a certified law enforcement officer must follow the proper procedures to ensure accurate results. The fact that a person’s actions interfere with the test while it is being conducted is enough to realize that this is a fallible method of testing, as humans are prone to making mistakes. Operational errors are all too common, as are technical errors if the machine used is not properly calibrated and maintained.
Blood tests are considered the most accurate of all methods to measure BAC, although they are also the most invasive. A blood test is taken at a hospital or at the police station, and may be requested by an officer who believes the breathalyzer test results are inaccurate. As with all chemical tests, the time that passes between when the suspect may have been drinking and driving to the time he or she is tested affects the results of the test.
Many errors can occur during a blood test to alter the suspect’s true BAC. Lab testing errors are common and include the lack of sterilization, preservatives and/ or proper refrigeration, and vial mix-ups. The blood itself can also undergo coagulation or fermentation, which can seriously affect the legitimacy of the test.
The urine test is the least used chemical test when testing a person’s blood alcohol concentration (BAC). It generally an alternative to the breathalyzer test and is used when a police officer suspects drug impairment. A urine test is typically performed at a police station or a hospital or clinic and, like the blood test, is considered an intrusive method.
As with all methods of chemical testing, a urine sample can be negatively affected by the lapse of time between when the drinking took place and when the test was taken. It can take up to 2 hours for alcohol to appear in a sample of urine. This means that, even if alcohol is present, the test can’t prove that the suspect was intoxicated at the time he was behind the wheel. The urine in a sample is also susceptible to alteration by the DUI suspect, who may be able to dilute the sample or substitute it with another substance.
If you face DUI charges in Palm Beach County, you need a strong and experienced criminal defense attorney to represent you. Brian Gabriel of The Law Office of Gabriel & Gabriel has spent 30 years defending individuals accused of DUI, theft, assault, and other crimes. Call 561-622-5575 today for a free consultation.