What is the pen test for DUI?
In almost every OUI case, the first field sobriety test that the officer administers is to ask the driver to follow his pen or some other stimulus with the driver’s eyes. Commonly called the “pen test”, this test is actually called horizontal gaze nystagmus (HGN).
What are the 3 clues for the HGN test?
There are a total of three clues that can be assessed in this test: lack of smooth pursuit, distinct nystagmus at maximum deviation, and the onset of nystagmus prior to 45 degrees.
How does the DUI eye test work?
As an object is moved in front of your eyes, across your field of vision, the officer will look for a visible twitch or quiver in your eyes as they follow the object, especially near the peripheral edges of your vision. If present, these movements show alcohol is present in your system.
How long should HGN test last?
approximately 88 seconds
In the following test one eye is look at a time. After the medical assessment is completed then the officer moves on to the HGN tests to evaluate impairment. IMPORTANT: The HGN Test should take approximately 88 seconds. If done too fast the test may have been improperly done.
What is the sobriety eye test?
The Horizontal Nystagmus Test (HGN) is a standardized field sobriety test (FST) that police often administer in order to gauge whether a DUI suspect is under the influence of alcohol. The officer notes the angle at which the pupil starts to exhibit “nystagmus” (involuntary jerking of the eye).
What is a Sfst test?
A SFST test is typically administered roadside and consists of a police officer putting a conveyance operator through a series of standardized sobriety tests. The evaluation includes sobriety tests that are similar to the SFST’s, taking clinical indicators (blood pressure, body temperature, pulse, etc.)
What is maximum deviation DUI?
The last clue is nystagmus at maximum deviation, which means that the eyes begin jerking within four seconds while looking all of the way to the side. If the officer observes four or more clues, he or she has probable cause to make an arrest for driving under the influence.
How accurate is Sfst?
Using the SFSTs, the officers were extremely accurate in discriminating between BACs above and below 0.08 percent. Estimates at the 0.08 level were accurate in 91 percent of the cases, or as high as 94 percent if explanations for some of the false positives are accepted.
What do cops look for when doing the eye test?
To conduct the test, the police officer is supposed to check the driver’s eyes to see that the pupils are of equal size and to see that the eye is able to track an object as it is moved side to side at eye level.
What are the clues on the DUI HGN eye test?
While moving the stimulus, the officer watches the driver’s eyes for three “clues” of intoxication: “onset of nystagmus prior to 45 degrees.” The officer counts the number of clues for each eye.
How does the nystagmus work in a DUI case?
Validity of the Nystagmus Test in DUI CasesUnder federal standards, the officer is supposed to use an objective scoring criteria for each of the three tests, and the total score determines whether the suspect passed or failed.
What kind of test is the horizontal gaze nystagmus?
Horizontal Gaze NystagmusYou may have heard of the “eye test” in DUI investigations. This is the nystagmus field sobriety test or, more accurately (there are 47 different kinds of nystagmus), the horizontal gaze nystagmus test.
How is nystagmus measured in a field sobriety test?
This type of nystagmus is commonly measured by the officer in three three different ways, each time using an object such as a pencil, penlight or finger placed a foot or so in front of the suspect’s nose and moving it slowly to the left and then to the right.