Question: If I voluntarily give a breath or a blood test, and my BAC is less than .08, can my license still be suspended?

Benson Varghese: There are two ways for your license to be suspended. One is obviously if you provide a sample and your sample is above .08. If you refuse, your license can be suspended, and those are the only two ways it can be suspended administratively. However, on the criminal side, which is completely separate, if you accept a jail sentence or if you are punished by a jury with a jail sentence, your license will be suspended for up to two years as a result of that criminal conviction. So later on down the line, there is a way for your license to be suspended. However, if you accept a probation sentence, your license will not be suspended.

Question: How accurate and reliable are methods used by the police to determine what the alcohol concentration is?

The state has the burden of proving that you were intoxicated at the time of driving. There is no perfect way to determine what your blood alcohol concentration was at the time of driving. Portable breath tests, which officers used to carry commonly, are not admissible for their results in court, because those devices are not calibrated, they’re not checked, and there’s no way to ensure that they’re accurate on any given day. The breath test devices that police departments purchase and maintain—and they have a technical supervisor whose sole job is to make sure that it’s functioning every day, throughout the county at various locations—they are testing at a point in time after you were driving. Additionally, when you provide a breath test in Texas, the instrument that they’re using does not have a breath trap; it doesn’t retain any evidence for later testing. You are tested, you provide two specimens at the time of that test and that’s it—it cannot later be tested or that sample can’t be scrutinized later. So that’s imperfect because there’s no way to come back and check that particular specimen to see if the reading was accurate.

Blood seems like a great option. The problem with blood is that by the time an officer gets you to a hospital to do the blood draw, time has elapsed and their burden is to prove that you were intoxicated at the time of driving, not an hour or three hours later. Additionally, blood can be tested in a variety of ways, but most often they’re sent to labs and you might be surprised to find out that they’re often sent in the mail. The blood files are sometimes kept in the back of the patrol car until the officer arrives at the station and takes it into custody and books it into—very often—a refrigerator in their evidence room. But there are times when that blood is not stored under ideal conditions or transported in conditions that are not ideal, and there are various ways that blood samples become unreliable.

So there's no perfect method for testing a person's blood alcohol concentration at this time.