How DUI Investigation and Standard Field Sobriety Tests Work

How DUI Investigation and Standard Field Sobriety Tests Work

Police use the same procedure for driving under the influence (DUI) investigations. The procedure often includes standard field sobriety tests. Understanding these tests will help you craft the best defense. 

The standard field sobriety tests came into force in the late 1970s as the brainchild of the National Highway Traffic Safety Administration (NHTSA). The Administration developed the testing to enhance the death rate on highways because of drunk driving. 

While the original studies had 16 tests, the NHTSA cut them to three primary ones. They are the walk and turn, the horizontal gaze nystagmus, and the one-leg stand. The police can deploy more tests. 

Standard Field Sobriety Tests (SFST) are under “divided attention tests.” It primarily focuses on evaluating a suspect’s ability to carry out the physical and psychological multitasking required for operating an automobile. 

Law enforcement agencies use the tests uniformly when they suspect a motorist to be under the influence of chemical substances or illegal drugs. The police will surely ask you to complete the tests when they suspect you to be driving under the influence. 

Police officers are designated experts in performing field sobriety tests. You must understand these tests to perform excellently as a DUI attorney.

Shedding Light on the Horizontal Gaze Nystagmus Test

Law enforcement typically administers an eye test first. An involuntary jerking of the eyes is “nystagmus.” Depressants like alcohol are responsible for this involuntary jerking. 

A law enforcement officer will focus on the three clues in each eye, searching for six possible clues in both eyes. The three clues include unique and sustained nystagmus at the eye’s peak deviation, nystagmus commencing before the eye gets to 45 degrees, and an absence of smooth pursuit. Displaying four or more clues means the suspect has failed the evaluation. 

The security agent will order the individual to stand with their feet together and push their hands to the side. Then, the officer will hold a stimulus, usually a pen, about 12 to 15 inches from the suspect’s nose. The stimulus should be slightly above the eye level. 

The stimulus gets to its maximum deviation within two seconds. However, the movement from one side of the face to the other happens within four seconds. The police will do the test repeatedly. 

It is essential to note that depressants lead to nystagmus. Training materials and manual opine that other drugs will not influence nystagmus. For instance, cocaine or marijuana cannot cause nystagmus. It is essential because breath or blood tests follow most field sobriety tests, which can establish the findings. 

What Walk and Turn Test Entails

Law enforcement agents often conduct the walk-and-turn test as the second assessment. This assessment determines your ability to remain balanced while carrying out a given maneuver. 

A suspect must maintain a position and heel-to-toe stance while the police reel out orders to perform this test. Then, the suspect will take nine heel-to-toe steps and turn before another nine steps back. You must keep a foot on the ground while turning. 

A law enforcement officer will observe the following in a suspect during the test:

• Inability to maintain balance during orders
• Commences too quickly
• Pauses walking
• Offline steps
• Misses heel-to-toe
• Inadequate turn
• Wrong number of steps
• Adopts arms for balance

A suspect who shows two or more clues has failed the assessment. An officer may observe some clues numerously during the assessment, but they will still count them as a clue. In other words, if a suspect misses the heel-to-toe step several times, it is still one clue. 

However, there are some mathematical issues with this evaluation. The police can detect four clues at 18 points during the assessment. A defendant can exhibit an additional four at a given point. 

Hence, there are about 76 points during the assessment that the police can observe a clue. According to the NHTSA, a suspect is intoxicated if they conduct 74 of 76. 

Again, the evaluation is mute on its validity to substances. The assessment interpretation and procedures are the same for weed, cocaine, alcohol, or any other substance. 

Understanding the One-Leg Stand Assessment

The police conduct the one-legged stand test as the last evaluation. This assessment requires a motorist to stand on a leg for thirty seconds. The evaluation is for coordination, balance, and ability to yield to instructions. 

The security agent will order the individual to raise their preferred leg six inches from the ground. Then, the defendant will count one to 30 aloud. The police will observe the process and focus on four potential clues. 

The clues include sways while balancing, hopping up and down, using arms to balance, and putting a foot down. 

You have failed the test if you exhibit two out of the four clues. You receive a clue no matter how consistently you act. If you hop up and down repeatedly, it remains one clue. It can be a source of questionable outcomes. 

Typical Issues with Standard Field Sobriety Tests

The universality of these tests is one of its primary issues. Regardless of the suspected basis of intoxication, the police will use them to assess a suspect. They will examine the individual under the influence of cocaine the same way they will test the suspect under the influence of alcohol. Hence, it appears too generic. 

Also, a law enforcement agent conducts the test if they think an individual is driving under the influence. The police stop and ticket numerous people daily, but they only use the standard field sobriety tests during a DUI investigation. 

“The police must find a reason for accusing a driver of being drunk before asking them to take the SFST. Thus, they must rely on the defendant’s driving pattern, confession of consumption, and other symptoms of intoxication. Slurred speech, smell of alcohol, and bloodshot eyes are typical intoxication symptoms,” says criminal defense attorney Maribeth Wetzel of Goldman Wetzel, PLLC. 

This means that the police will have logical reasons to assume that a suspect is intoxicated before conducting a test to determine the truthfulness of their assumption. You cannot equate these tests to intoxication levels according to Florida law. 

Also, law enforcement cannot say the test results would equate to a suspect with blood alcohol content greater than 0.08 percent. Instead, they must affirm a suspect did not carry them out as a sober individual would.