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This article is a continuation of earlier articles that have went through DUI arrest from the time of the pullover until the time of the arrest and further.

earlier we went through the pullover some ot the signs of a person being under the influence and some of the objective symptoms. 

Also, we touched on the preliminary test and the non standardized versus standardized testing.  we continue that below.

ONSET OF NYSTAGMUS PRIOR TO 45 DEGREES (CLUE NUMBER THREE) This clue is present if a person eyes start to jerk before they reach 45 degrees.  Officers are trained to estimate 45 degrees two different ways. 

Using 15 square template that is cut diagnally.

Approximately equel to the edge of a person’s shoulders

DRE qeustions using formula to prove BAC between .00 and .05%

Officers are trained that the three Standardized Field Sobriety elements are as followed:

1. Standardized Administrative Procedures

2. Standardized Clues

3. Standardized Criteria


Stanndardized Field Sobriety Tests Setup Questions.



Step 1 Check for eyeglasses Instruct subject to remove eyeglasses

Step 2 Vertical Instructions

put feet together hands at the side

keep the head still

look for stimulas

follow movement of the stimulas with eyes only

keep looking for the stimulas until the test is over

Step 3 Position the stimulas Position the stimulas approximately 12-15 inches in front of the subjects nose and slightly above eye level to commence the test


Resting Nystagmus may be observed at the time.  Officers should note whether the subject displays Resting Nystagmus.

Step 4 Equel Pupil Size and Resting Nystagmus.

Step 5 Check for equel tracking.  The speed of the stimulas should be approximately same speed used as checking for the lack of smooth pursuit.  Make at least two complete passes in front of the eyes. There should be at least two complete passes in front of the eyes.  There should be a clear distinguishable break between the check for equel tracking and lack of smooth pursuit.

If a person has unequel pupil size resting nystagmus or unequel tracking it suggests the person is likely to have medical conditions or injuries that would cause nystagmus to be present.  Some seizure medications also cause nystgmus. 

If  a person has an obvious eye condition such as an artificial eye. the HGN test should not be administered. 


It is necessary to move the object smoothly in order to check the eyes ability to pusue smoothly. the stimulas should be moved from center postiion.  all the way back across the subjects face all the way out to the left side where the eye can go no further (checking the subjects right eye) and then go back to the center. 

The object must be moved steadily at a speed that takes approximately 2 seconds to bring eye from center to side. 

In checking this clue make at least two complete passes in front of they eyes. 


Check the right and left eye for the “Distinct and Sustained Nystagmus at Maximum Deviation” clue.  If the jerkiness is distinct and sustained  that is one clue.


Next blog post we will continue on the factors that the officer must take into consideration before making an arrest for Driving Under the influence after that blog post we will take a break from the factors in determining whether to arrest for DUI and will look at other issues in the law including Not Guilty by reason of Insanity Law.

Gerald Schwab, Jr.


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Phone: 559.441.1418