A.R.S. § 28-1381-1383: Driving or Actual Physical Control While Under the Influence

Arizona has a zero-tolerance policy on driving under the influence (DUI) and is known to have extremely strict and dynamic DUI laws. Because of this, police officers are trained on how to recognize drivers who are under the influence and how to perform field sobriety tests. There are different stages to the DUI investigation and in each portion the driver has constitutional rights the police must respect. There are three main stages of the DUI process: the traffic stop, the investigation, and the arrest.

The Traffic Stop

Generally, officers must have reasonable suspicion of a traffic violation, be responding to a car collision, or performing a welfare check to be able to make initial contact with a driver. Because driving is a task that requires the ability to think, react, and perform quickly while multi-tasking, there are certain violations a police officer is looking for. Typical violations that officers will stop with suspicion of a driver possibly under the influence include swerving in between lanes, speeding or driving far below the speed limit, making wide or improper turns, or failing to use turn signals. Officers can still perform traffic stops for violations that do not raise such concerns of driving under the influence such as having a broken taillight, improperly displayed license plate, or expired registration. When an officer observes any traffic violation, he can perform the traffic stop and make contact with the driver.

Officers also respond to reports of any car collision to help the parties involved. Even if the driver did not call or ask for aid, the police officer can make contact with the driver. Also, officers can perform welfare checks on drivers without there being any traffic violation. They may check on a vehicle that has been stopped at green light through different light cycles or vehicles on the side of the road. These welfare checks also do not need the driver to call for the officer to make contact. Whether it is by traffic stop, responding to a collision, or performing a welfare check, after making contact with the driver, officers then can make observations to build reasonable suspicion of possible DUI.

Once stopped, the officer will look for different signs and symptoms of impairment. These symptoms include bloodshot watery eyes, slurred speech, odor of alcohol, flushed face, confused or daze expression, difficulty handing documents over, and balance issues. If an officer observes any number of these symptoms of impairment, he will have reasonable suspicion then to conduct a DUI investigation.

The DUI Investigation

Now that the officer has reasonable suspicion to investigate for DUI, he next needs probable cause in order to make an arrest. The officer builds probable cause through having the driver perform Field Sobriety Tests (FSTs). There are a number of tests officers can use, but the three most standard and common tests are the Horizontal Gaze Nystagmus (HGN), the Walk and Turn, and the One Leg Stand. The HGN test is the eye test where an officer will track the driver’s eyes with a pen. This test is to observe the involuntary jerking of the eyes and lack of smooth pursuit. The Walk and Turn test observes the driver’s ability to maintain balance and follow directions properly. The One Leg Stand test also helps to identify any issues with swaying and ability to listen and follow instructions. Other FSTs include tests that measure mental awareness and dexterity. The Rhomberg test measures mental stamina as the driver is required to recite the alphabet backwards, count downwards, or measure the passage of 30 seconds. The Finger to Nose and Finger Count tests examine hand-eye coordination and dexterity.

While administering these tests, officers will take notes of any clues of impairment. For each test, the officer is looks for different clues that show the driver is impaired. For example, in the Walk and Turn test, the officer looks to see if the individual cannot keep balance, follows instructions, stops while walking, does not touch heel to toe, steps off the line, raises arms, makes an improper turn, or takes the incorrect number of steps. Each test has different types and number of indicators. The HGN test has 6 clues, the Walk and Turn has 8 clues, and the One Leg Stand has 4 clues. The officer will notate how many and what clues he observed. The last test the officer will use is the Preliminary Breath Test (PBT) which is similar to breathalyzer in that it identifies the Blood Alcohol Concentration in the breath of an individual.

Reliability of FSTs

Upon conclusion of these tests, if the officer observed sufficient clues of impairment, he would have probable cause to arrest the driver. However, it is not clear what is sufficient to show probable cause or how reliable these tests are. The National Highway Traffic Safety Administration is responsible for the regulation and training of field sobriety tests. In one NHTSA training manual, the NHTSA analyzed research test data from the Southern California Research Institute (SCRI) to determine the accuracy of each test by itself and found the HGN was 77% accurate, the Walk and Turn was 68% accurate, and the One Leg Stand was 65% accurate.

There are a number of concerns with the validity of these tests and their reliability in showing impairment. All tests, minus the PBT, can be testified to at trial by the officer where he will explain the test, what he measures, and how the driver performed. This is particularly concerning as there are many factors that can affect one’s performance on FST’s. Some factors that can affect the performance on the FST are: location of the tests and lighting, weather and traffic conditions, age and weight of the driver or any prior or current medical conditions, the driver’s shoes, any language barrier or the clarity of the officer’s instructions. Many times, a driver will still be subjected to tests even if they indicated prior injuries or possible difficulty performing the test. Also, there are concerns whether the officer correctly observed the clues. Body worn camera has helped to identify these incorrect observations, but still much can be done. The NHTSA manual addresses the concern over the validity of these tests and improper conditions:

The procedures outlined in this manual describe how the SFSTs are to be administered under ideal conditions. We recognize that the SFSTs will not always be administered under ideal conditions in the field because such conditions do not always exist. Even when administered under less than ideal conditions, they will generally serve as valid and useful indicators of impairment. Slight variations from the ideal, i.e., the inability to find a perfectly smooth surface at roadside, may have some effect on the evidentiary weight given to the results; however, this does not necessarily make the SFSTs invalid.

Because these tests lead to the arrest of the driver and can be used against him at trial, it is important to have a team of dedicated attorneys to help your case. Whether it is challenging the validity of the stop, the administration of any of the field sobriety tests, or the procedure of obtaining a warrant or fighting for better terms of a plea deal, an experienced attorney will navigate this process with you. At Mesa DUI Lawyer, you get top-notch representation with personable communication - call today.