Can a blood alcohol test ever be wrong?

Those accused of driving while intoxicated (DWI) in Texas often face charges backed by chemical evidence. Usually, police officers are asked to perform a breath test as part of a DWI traffic stop. However, in some cases, such as when a driver refuses a test and officers must obtain a warrant, there may be a blood test on record rather than a breath test. 

Not every breath test is accurate. Some Breathalyzer devices can be improperly handled, miscalibrated or outright defective. What about blood tests? Is there any possibility that a blood test that says you were intoxicated is wrong?

Fermentation can occur after a blood sample is taken

Contamination or improper storage could alter the accuracy of a blood test performed on a sample. If the sample of blood sits for a while, microbial contamination could result in fermentation and produce alcohol. 

Although researchers have shown that such fermentation doesn’t occur in acceptable laboratory settings, such research doesn’t prevent a challenge to blood-based chemical evidence of impairment. Storage temperature and many other factors could potentially result in the creation of alcohol, especially if the blood sample begins to decompose. 

It is possible for a poorly-stored blood sample to produce alcohol after police officers take the blood sample. Any records or evidence that support the possibility of contamination, storage that lasted too long before testing or significant temperature fluctuations during storage might help build a defense strategy that challenges the validity of a blood test. 

If you’re facing a DWI, call an attorney

Challenging the accuracy of a chemical test is one possible way of defending yourself, but there may be other defense options available to you depending on the circumstances of your case.