If an officer stops you in Maryland because he or she suspects you of DUI, a field sobriety test is likely to form part of the stop. There are several tests designed to gauge the impairment of your basic functions were.
There are three major types of tests known as the Standardized Field Sobriety Tests. The National Highway Traffic Safety Administration describes these tests and sets forth the correct way of administering them. If an officer administers the tests incorrectly, the results may fail to stand up as evidence against you.
You do not have to agree to take the test
The law does not require you to comply with a police officer's request to take a field sobriety test. Typically, officers use the results of the test to justify an arrest and the ensuing mandatory breath test.
Horizontal gaze nystagmus
The horizontal gaze nystagmus is a test that focuses on your eye's function, which alcohol or drugs can affect. The officer will ask you to track an object such as a pen using solely your eyes without moving your head. Inability to track with a smooth motion of the eye can be a sign of impairment.
The one-leg stand test consists of asking you to count to 30 while standing on a single leg. During this test, officers will be seeing whether you are able to balance easily and whether you are able to count correctly and at a normal pace.
Walk and turn
The walk and turn test has two parts to it. First, the officer will tell you to stand with your right foot in front of your left and your arms at your sides. While you stand in this position, the officer will tell you about the next stage of the test. Standing incorrectly or beginning to walk before the officer tells you to can count against you.
The actual walk and turn consists of a series of specific, stylized motions which purposely differ from the natural way most people would move. This is a test of both physical coordination and the cognitive ability to follow instructions.
Sober people may fail field sobriety tests
Factors other than impairment can cause a person to fail an SFST. These may include health conditions that affect balance, nervousness or even the type of shoes they happen to wear.