Driving Under the Influence laws have evolved to encompass a wide range of dangerous driving to make roads safer. Police officers get specialized training to spot intoxicated driving. If a law enforcement officer stops you on suspicion of driving under the influence (DUI), you may have questions about what to expect.

Part of the DUI process will involve determining if you are under the influence of alcohol or drugs. Police officers often use field sobriety tests to look for signs of intoxication.

Field sobriety tests (FSTs), sometimes called roadside sobriety tests, help enforce DUI laws and usually precede chemical tests, such as Breathalyzer tests or other breath tests, as well as blood, saliva, and urine tests. All sobriety tests ensure that an officer has probable cause to arrest someone for driving under the influence.

A police officer typically performs three types of field sobriety tests during a traffic stop: 1) The horizontal gaze nystagmus test, 2) The one-leg-stand test and 3) The walk-and-turn test

These tests allow an officer to observe your balance, physical ability, attention level, or other factors that the officer may use to determine whether you are driving under the influence of drugs or alcohol. Officers will likely record your performance on field sobriety tests for evidence should you receive a DUI charge.

The National Highway Traffic Safety Administration (NHTSA) endorses the Standardized Field Sobriety Test (SFST). Standardized tests are performed in the exact same manner every time to be accurate and admissible in court. To ensure this consistency, police officers undergo extensive training in performing FSTs.

The term “horizontal gaze nystagmus” refers to the involuntary jerking of the eye that occurs naturally when the eye gazes to the side. This jerking, or nystagmus, becomes exaggerated when you are under the influence of alcohol. Officers look for three indicators of impairment in each eye: 1) Inability to follow a moving object smoothly, 2) Distinct eye jerking when the eye is facing the farthest from center and 3) Eye jerking when the eye is 45 degrees off-center.

This test aims to gauge your ability to complete tasks with divided attention. Most unimpaired people efficiently do this task. The police officer will direct you to take nine steps, heel-to-toe, along a straight line. Then, you turn on one foot and return in the same manner in the opposite direction.

The officer asks you to stand with one foot about 6 inches off the ground and count for 30 seconds. Swaying while balancing, using arms to balance, hopping, or putting the foot down indicates possible impairment.

Taken as a whole, the results of field sobriety tests accurately indicate alcohol impairment with a blood alcohol content (BAC) of 0.08% in 91% of all such cases. This level rose to 94% of cases if explanations for false positives were accepted, according to a 1998 study cited by the NHTSA. Suspects who fail FSTs are usually given a preliminary alcohol screening (PAS) to determine their blood alcohol concentration before an arrest. This may be a Breathalyzer or other breath tests.

Before performing FSTs during a traffic stop, the police officer should ask you about any medical conditions, disabilities, or injuries, as these can affect the accuracy of the tests. The officer will also consider your age, current medications, or other conditions in determining if FSTs are appropriate. For example, an inner ear condition or multiple sclerosis may make you unsteady, causing test failure.

If you or a loved one is in a bind as a result of a criminal charge, immediately contact a Seattle Criminal Attorney. A Criminal lawyer is not going to judge you and understands that everyone makes mistakes. Hiring a Seattle Criminal Lawyer to help can – at a minimum – reduce penalties and can help direct people on how to best deal with their criminal charge, and many times even get them dismissed. So, it should go without saying that someone cited for a misdemeanor or felony should hire a qualified Seattle Criminal Lawyer as soon as possible. Criminal charges can cause havoc on a person’s personal and professional life. Anyone charged with a crime in Washington State should immediately seek the assistance of a seasoned Seattle Criminal Lawyer. SQ Attorneys can be reached at (425) 359-3791 and/or (206) 441-0900.