Las Vegas, NV- When a police officer pulls a motorist over they suspect of being intoxicated, they will ask that motorist to participate in field sobriety tests. These tests allow an officer to determine if a motorist is intoxicated and gives them the evidence they need to justify a DUI arrest. In this article our DUI lawyers in Las Vegas will discuss field sobriety tests and how reliable they are.

The first thing an officer will look at is the motorist’s eyes to see if they are bloodshot or glassy, two of the many signs of intoxication.  They will also listen for slurred speech. If an officer even gets a whiff of alcohol or notices any one of those signs, the motorist will then be put through a battery of sobriety tests.

There are a number of field sobriety tests law enforcement uses in the field but there are four that are commonly used.

Here is a brief description of each of those tests as outlined by the National Highway Traffic Safety Administration:

HGN Test- the Horizontal Gaze Nystagmus is an involuntary jerking motion of the eye and occurs when person looks to either side. It occurs when the eye is rotated at high peripheral angles, but when a driver is intoxicated, the jerking motion will be exaggerated or will occur at lower peripheral angles. Intoxicated drivers also have difficulty following moving objects with their eyes. According to the NHTSA, the HGN test is 88 percent accurate.

Walk and Turn and One Leg Test- Both of these tests are called divided-attention tests and pretty easy for a sober person to perform. These two tests require a motorist to engage in a physical activity while listening to an officer’s instructions. The point is to divide a motorist’s attention between a physical and mental test.

For the Walk and Turn, the suspect is asked to take nine steps, heel to toe. Once those steps are complete, the suspect is then asked to turn on one foot an repeat the steps. Officers look for eight signs of impairment which: Can the suspect can maintain their balance? Do they have to use their arms to balance? Can they walk a straight line? And are able to turn without losing their balance?

The One Leg Test is pretty straightforward, the suspect is asked to stand on one leg and count aloud or recite the alphabet. This is usually an easy thing to do sober, but it can be very difficult for an intoxicated person to maintain their balance and perform a mental task. The NHTSA estimates that the Walk and Turn test has a 79 percent accuracy rate, while the One Leg Stand has 83 percent accuracy.

If a driver performs poorly on these tests, they will most likely be asked to submit to a breathalyzer or chemical blood test. Refusing these tests can be good or bad, but that really depends on the circumstances of each person’s case.

The results of field sobriety tests can be convincing evidence, so any motorist who is facing a DUI charge needs to get expert legal advice. USAttorneys can connect you with a DUI lawyer located near you in Las Vegas to help you with your defense.