If you’re stopped and arrested for driving while intoxicated, you may have a breath, urine or blood sample taken. If you have your blood drawn for the test, the lab will mix it with specific chemicals to determine how much alcohol is in your blood. The blood test may also reveal other information, such as if you had any drugs in your system at the time of the arrest.
Blood tests are not infallible, which is something many people don’t realize. It’s still possible to get false positive results, and it’s also possible to end up with results that don’t really reflect the truth about drug use. If you are facing a DWI, it’s very important to challenge the results.
It’s possible to get a false positive for drugs
One thing to know about DWIs is that they aren’t just for alcohol. If a blood test is done and you have drugs in your system, you can face a DWI as well.
The problem with blood tests is that they have a tendency to pull false positives when you’ve ingested items that break down similarly to other drugs. For example, if you take a cold medication containing dextromethorphan, you could test positive for opiates or PCP. Benadryl, a common allergy medication and sleep aid, can also trigger a positive result for opiates, PCP or methadone.
An alcohol-related DWI could be a false positive, too. How? If the wrong test tube is used, if air gets into the test tube and allows the blood to ferment or if other unusual circumstances occur, the sample may no longer be pure and could turn out with a false positive.
You need to question the results of any DWI tests
It’s important for you to know that you can question the results of any blood alcohol concentration or drug tests that you take following a DWI stop. It is possible for those test results to be wrong, in which case you deserve the opportunity to fight back. You may be able to prove your case and minimize or eliminate the penalties you could otherwise face.