Using the HGN test to your advantage

"I am going to check your eyes. Keep your head still and follow this stimulus with your eyes only. Keep following the stimulus with your eyes until I tell you to stop."

So begins the administration of the horizontal gaze nystagmus (HGN) test to the suspected drunk driver. The officer then begins the magical process of waving a pen back and forth in front of the driver's eyes to determine if he or she consumed any alcohol. Nevermind that, by that point, the driver has usually admitted to drinking "a couple" of beers or mixed drinks.

But instead of looking for signs of impairment, let's look for some signs that our driver is not impaired. Did the driver keep his or her head still? Did the driver follow the movement of the pen with his or her eyes? Was the driver standing still?

In order for the officer to administer the "test" correctly, he must be able to look into the driver's eyes. In order for him to look into the driver's eyes, the driver must be standing still and not swaying. The stance the driver takes during this test is the most normal stance he or she will take during the administration of the standardized field sobriety tests (or, as I prefer to call them, the police coordination exercises).

In order to "take" the pen and eye test, the driver must exhibit some fine motor skills. He or she must stand still and, without moving his or her head, follow an object being passed in front of the eyes. The driver must also understand the directions he or she was given by the officer - a test of mental faculties.

Think about it, if the driver can't stand still, can't keep his head still, can't follow the pen with his eyes and can't follow directions, the officer can't complete the test.

Therefore, the very fact that the officer completed the administration of the HGN test demonstrates that the driver still had the use of his or her mental and physical faculties.

Passing before our eyes

I find it a bit ironic that the most "scientifically valid" standardized field sobriety test is also the one that jurors are the least concerned about. I am, of course talking about the horizontal gaze nystagmus (HGN) test.

At trial the prosecutor and arresting officer will do their little "dog and pony show" about how the driver's jerky eyes indicates that he must be intoxicated. The officer will testify (usually) that he found all six clues when administering the test and that the only logical conclusion is that the driver was intoxicated at the time he was driving.

Of course if you take out a stop watch while viewing the video it becomes evidence quite quickly that the officer didn't administer the test correctly. Either he moved the pen too quickly or too slowly in front of the driver's eyes or he held the pen too high or too low when making the passes.

Do you file a pretrial motion to suppress the test, file a motion in limine requesting the opportunity to take the officer on voir dire before he testifies about the HGN test, do you conduct a vigorous cross examination of the officer on his mistakes or do you gloss over the test and move on to other topics?

Here's a little hint...in most jurisdictions when the jury watches the video all they see is your client standing still with the officer waving a pen in front of your client's face. The jurors don't see your client's eyes jerking. In fact, you can often score points with the jury by asking the officer if your client stood still, didn't sway and didn't move his head back and forth.

Jurors are far more concerned with how your client did on the Walk and Turn and One Leg Stand tests because that's when they get to see if your client "looks drunk." Those are the tests to attack hard and often.

I tend to ask a few questions about the "pen and eye test" and then move on to more fertile ground -- unless the officer butchered the test to such a degree that it casts his entire investigation into question.

The eyes have it

Arresting officers in DWI cases love to get on the stand and announce that your client exhibited all six "clues" in the horizontal gaze nystagmus (HGN) test and, as a result, it was a foregone conclusion that your client was intoxicated.

But wait just a second - even though this "test" is couched in scientific terms, the follow-the-pen show on the video is far from being either scientific or valid.

Nystagmus is defined by NHTSA as "an involuntary jerking of the eyes." NHTSA states that alcohol causes horizontal gaze nystagmus.

The American Academy of Opthamology defines the condition as "is an unintentional jittery movement of the eyes" that "usually involves both eyes and is usually exaggerated by looking in a particular direction."

So, for your police officer trained to diagnose eye conditions by another police officer, nystagmus is an indicator of intoxication. To a trained medical practitioner, however, nystagmus is a medical condition.

When an officer detects "nystagmus" someone is likely to be placed under arrest and hand-cuffed. When a trained medical practitioner detects nystagmus, on the other hand, he is going to conduct a thorough evaluation and will more than likely call in another specialist to examine the patient.

When an officer conducts the pen-and-eye test in the field, there are no controls for the effects of weather, lighting or traffic conditions. The officer must estimate the time for each pass of the pen and the distance the pen travels to the side. When a trained medical practitioner conducts an eye test to determine if nystagmus is present, the test is performed in a controlled environment with medical instruments by a doctor who went to medical school.

Finally, when an officer detects "nystagmus," he is looking for evidence to confirm his suspicion that the motorist is intoxicated. When a trained medical practitioner detects nystagmus, his job is to eliminate all possible causes until he can diagnose the underlying cause.

The scientific literature indicates a myriad of conditions responsible for nystagmus - from epilepsy to Parkinson's disease and from muscular dysfunction to head trauma. But, according to the police officer's diagnosis, the only cause for nystagmus of a driver being tested at the side of the road is alcohol consumption.

We're trained professionals

According to the NHTSA Manual entitled DWI Detection and Standardized Field Sobriety Testing, when conducting the horizontal gaze nystagmus (HGN) test, the officer is to check the suspected drunk driver's eyes for pupil size, resting nystagmus (involuntary jerking) and tracking ability. The manual states that if "the eyes do not track together, or if the pupils are noticeably unequal in size, the chance of medical disorders or injuries causing the nystagmus is present."

Presumably this would also include drivers who are blind in one eye.

Not, however, according to Officer Chris Murray of the Pasadena (Texas) Police Department. On December 14, 2008, Officer Murray, while offduty, stopped a driver he suspected of driving while intoxicated. Per Officer Murray:

I performed the Horizontal Gaze Nystagmus test on the suspect, and during the pre-test check, I noticed that the suspect's left eye appeared to have some sort of deformity. The pupil was not readily visible, the brown part of the eye was cloudy. I asked the suspect about the problem, and he told me he was blind in one eye. The suspect's eyes however, tracked normally. The suspect had a lack of smooth pursuit in both eyes, a distinct sustained nystagmus at maximum deviation, and an onset of nystagmus prior to forty-five degrees. The six clues (three for each eye) were a strong indicator of intoxication. (emphasis mine).

It's common place to see every officer claim to have observed all six clues for every driver they test, but it's a bit out there to find an officer who claims to have observed these clues in an eye out of which the driver can't see.

HGN and hearsay

The Amarillo Court of Appeals has reversed a DWI conviction because the trial court allowed the prosecutor to introduce a letter from the American Optometric Association regarding the validity and reliability of the horizontal gaze nystagmus test. 

In Wells v. State, No. 07-07-0471-CR (Tex.App.--Amarillo, 2008), the Court held that it was reversible error for the trial court to have allowed the arresting officer to identify the letter and then to allow the prosecutor to read it into evidence.  The Court pointed out that there was nothing in the record to indicate the officer was an optometrist, a member of the AOA or had any knowledge of any test or studies that backed up the AOA's position.

Interestingly enough, the prosecutor introduced the exhibit at the end of the state's case in chief (at the end of the first day of trial) and reintroduced it during closing argument.  Defense counsel (correctly) objected on the grounds that the document was hearsay and that the defendant was being denied his right to confrontation under Crawford.

Now when the prosecutor asks the arresting officer about the so-called validation studies and the supposed accuracy of the NHTSA battery of police coordination exercises, stand up and object with the Wells opinion in your hand.