A similar scenario occurs in many DWI traffic stops. The police pull over a vehicle for a traffic infraction. The officer approaches the window and smells an odor of alcohol coming from the driver. The officer asks the driver if they have been drinking, and the driver acknowledges having had a couple of beers at dinner. Although nothing is illegal about drinking a couple of beers (or cocktails, or glasses of wine, etc.) and driving home, the officer immediately asks the driver to exit the vehicle and initiates a DWI “investigation.”

The law in Texas, like every other state, is that it is legal to operate a motor vehicle with alcohol in your system as long as you are not intoxicated. Intoxication in Texas is defined as having lost the regular use of your mental or physical faculties due to the introduction of alcohol or other drug into your body or having a blood alcohol content (BAC) of .08 or higher. Of course, an officer can never know whether or not a person has a  BAC of .08 when they are on the side of the road, so they are left to determine whether there is probable cause to believe someone has lost the regular use of their mental or physical faculties. How do they make this determination? They rely heavily on the so-called Standardized Field Sobriety Tests (SFSTs).

In theory, these SFSTs are designed to provide officers in the field with reliable information to assist them in making a correct DWI arrest decision. However, these tests offer nothing more than cover for an officer to justify their intended arrest. 

What are SFSTs?

There are three basic Standardized Field Sobriety Tests. The Horizontal Gaze Nystagmus (HGN), Walk and Turn (WAT), and the One Leg Stand (OLS). All three of these tests are designed to be taken together, and the police are trained to look for “clues” of intoxication for each one. Each test has a certain number of “clues” that police are looking for, and if they see a specific number, they will determine that the person failed the test.

Incorrectly Administered Tests are NOT reliable

As noted by the name, they are designed to be conducted in a standardized way with the same instructions given to everyone, and they are designed only to be given to someone who is a proper candidate for the tests. For example, if someone has a history of back, neck, or head injuries, then that person would likely not be a proper candidate, and the test should not be given to them. This makes perfect sense since that person would likely exhibit the “clues” an officer would look for. Still, the officer would have no idea if those “clues” were related to intoxication or the person’s physical limitations.

Unfortunately, in numerous cases, the officer performs the tests incorrectly, or they are given to people who are not proper candidates for the tests. Oftentimes, the police officer will acknowledge these mistakes and admit that due to these mistakes, the validity of the test results is compromised. So, what do prosecutors typically do in these instances?  They present these invalid results to the jury anyway and argue that these “small mistakes” don’t matter and that jurors should convict them based on these faulty tests. 

Correctly Administered Tests are also NOT reliable

While many people may be surprised to learn that admittedly unreliable results are routinely used to convict people of DWI, people tend to believe that these tests, if performed correctly, are reliable. As an attorney who has handled hundreds of DWIs and who has tried many cases on juries, these tests are seriously flawed in a fundamental way.

Here’s an example. Let’s take the Walk and Turn (WAT) test and assume that it is performed 100% correctly by the officer and that the person taking the test is an ideal candidate for the test. Essentially, the WAT requires someone to take nine heel-to-toe steps down an imaginary line, turn around, and take nine heel-to-toe steps back. 

The WAT has 8 “clues” the officer is looking for

1. Unable to maintain balance while listening to instructions 
2. Beginning the test before you are told to begin, 
3. Stopping while walking the imaginary line, 
4. Taking a step entirely off the line, 
5. Missing heel-to-toe on one of the steps, 
6. Using your arms to balance, 
7. Making an improper turn
8. Taking the wrong number of steps.

So, imagine you are pulled over for DWI and asked to perform these field sobriety tests. It is dark, and you are on the side of the road where 2-3 police officers are hovering over you and asking you pointed questions that make it clear that if you fail these tests, you are going to jail. The officer properly instructs you on how to perform the test. You are excited and nervous and start taking the 1st step. The officer tells you, “Hold on. I haven’t told you to start yet.” You relax and wait. He tells you to begin. You take nine perfect steps. All on the line and all heel-to-toe. You never use your arms for balance, never lose your balance during instruction, and never stop while walking. You make a perfect turn. You take nine steps back. The first eight are perfect – all on the line and all heel-to-toe. On the last step, the 18th total, your feet remain correctly on the line, but the gap between your heel and toe is ¾ of an inch. Otherwise, it’s perfect.

Guess what? You just failed the WAT test. You started too soon and missed one heel-to-toe step (yes, just 1 of 18). Those are 2 “clues” you have exhibited. According to the police standards, if you have 2 of 8 clues on this test, then you have failed the test. Further, the officer will appear at trial and inform the jury how, in his training and expertise, these results support a DWI conviction.

Does this sound like a test that is designed to determine whether or not someone is intoxicated, or does it sound like a test that is intended to convict anyone who is arrested for DWI?