Horizontal Gaze and Nystagmus Test

Many who come in for an initial office appointment to discuss their Massachusetts OUI charge wonder, what was the pen test all about. This test is formally known as the Horizontal Gaze and Nystagmus test. Most refer to the test as the pen test because officers will waive a pen in front of your face making observations. Typically, officers do not perform this test correctly and the results lack any reliability in court.

Under Massachusetts OUI law, the HGN test is almost never entered into evidence in court. Accordingly, the results of this test will have little to no impact on the outcome of your case. The reason that the results do not get admitted into court is based on the Massachusetts Supreme Judicial Court decision in Commonwealth v. Sands, 424 Mass. 184 (1997), which held that prior to admitting the HGN test the Commonwealth must establish that the officer can testify as an expert as to his administration of the HGN test. The Commonwealth typically does not attempt to admit this test into evidence at a drunk driving trial.

Despite the fact that the test is generally not admitted into evidence, I will explain the purpose of the test and how the officer should administer the HGN test. Ironically, the HGN test is considered the most reliable of the standardized field sobriety tests at 77% reliable. While the test is not used in Massachusetts DUI trials, it is widely used throughout the country.

What is nystagmus? Nystagmus is considered an involuntary or abnormal movement of the eye, usually referred to as jerking of the eyes from side to side or up and down. In Massachusetts DUI arrests, only the horizontal nystagmus is used in court as vertical nystagmus is typically limited to case involving DUI/OUI drug arrests.

Causes of Nystagmus: Alcohol is one of many cause of nystagmus. Other causes of nystagmus include problems with the inner ear, physiological problems, sickness, fatigue, nicotine and caffeine to name a few of the cause of nystagmus other than alcohol.

What is the officer doing when he waives the pen in front of my face for the HGN test? An officer is suppose to be observing the following three clues:

Lack of smooth pursuit. When the officer moves the pen, the officer is looking for whether the eyes track the stimuli smoothly without jerking or bouncing.

Distinct and Sustained Nystagmus at Maximum deviation: this is when the officer moves the pen to each side until the eye has gone as far as possible. The officer then is suppose to hold the pen for four seconds to see if there is any involuntary jerking of the eye or nystagmus.

Onset of Nystagmus Prior to 45 degrees: The officer looks to see if there is any involuntary jerking of the eye prior to 45 degrees when moving the stimuli. The officer is suppose to move the stimuli slowly at a speed that would take four seconds to reach your shoulder.

Flaws in administering the HGN test: Many officer move the stimuli rapidly in front of a motorist's face. When properly performed the test should take about 81 seconds to execute the number of passes for each eye at the correct speed.

While the HGN test is generally not admissible, in some cases, an experienced Massachusetts OUI attorney may want to allow the test into evidence to discredit the officer and undermine the lack of compliance with police training in administering field sobriety tests.

To discuss your Massachusetts OUI/DUI charge, call 781-686-5924 or 508-455-4755; I would be happy to explain the HGN test and other field sobriety tests in greater detail at a free office appointment.