DUI Expert Witness Advises on The Most Overlooked Element in Winning or Losing a DUI Case

This article was authored by a DUI expert witness with nearly 20 years experience as a police officer. He is also a field training officer at a county police department and serves as the Vice President of a nightclub security consulting firm.

The Most Overlooked Element in a Winning or Losing a DUI Case: Is the Officer Properly Trained to Determine Probable Cause?

It seems that more and more defense attorneys are challenging Driving Under the Influence (or DWI) cases simply because they really have nothing to lose. In addition, plea-bargaining is not usually in the best interest of their client. There are virtually dozens of holes that a good defense argument can attack in these types of cases. These include the traffic stop, the officer’s investigation, or the breath/blood test. Police officers are specifically trained on how to locate and conduct a proper DUI investigation. However, they often make a number of errors that do not conform with their training. Not only does it pay to know this information on the defense side, but prosecutors should also be aware of the training and ensure the cases officers are performing correctly.

Police officers across the nation are often trained under nationally recognized standards developed in 1977 by the National Highway Traffic Safety Administration (NHTSA). These Standardized Field Sobriety Tests (SFST) have been in place for over forty years. The SFST battery consists of Horizontal Gaze Nystagmus (HGN), Walk and Turn (WAT), and One Leg Stand (OLS) – executed in that order. The training was developed using research-based data that helps officers make OBJECTIVE observations of specific clues. This assists them in determining whether someone is impaired or intoxicated. By using standardized elements and administrative procedures, a well trained police officer can make a “correct” arrest decision based on objective (not subjective) determinations of impairment.

With the research backed data from NHTSA, the International Association of Chiefs of Police (IACP) helped to promote the training to agencies and officers across the country to help reduce DUI and DWI fatalities. Using these standardized elements, officers are trained over a (mandated) 24 hour period. They are taught during this time how to locate and correctly identify impaired drivers. They are also taught to make an arrest based on the objective clues they see. While this was (and is) the goal of the training program, police officers are often not properly trained. Therefore they fail to sufficiently implement their training in the field.

The NHTSA SFST training teaches three phases of detection: Vehicle in Motion, Personal Contact, and Pre-arrest Screening. Most defense attorneys attack and argue the stop (Phase 1 – Vehicle in Motion) in a motion to suppress hearing. However, they are often choosing not to focus on the area where most officers make mistakes during their investigation, Phase 3 – Pre-arrest Screening. In the SFST training the officers are taught to follow the standardized elements and not deviate from the training they received. Doing so will render the tests “inherently unreliable” (see: State V. Homan, 732 N.E.2d 952, Ohio 2000). The Homan case indicates that even “minor deviations” can create a bias in the results. This defeats the ability of the officer to rely on the results of the tests.

During in class training, officers practice often and must pass a test and a skill based assessment. Then they receive a certificate allowing them to use the tests in the field. The program is rigorous and standardized for each instructor to follow in providing the training and evaluations.

While many officers complete the training and evaluations, they do not practice the skills. Many times they see other officers using different tests (or variations) in the field and deviate from the training they received. Here in Virginia, many basic police academies have only taught DWI detection and a portion of the SFST program up until the full 24-hour program was put in place in January 01, 2014 as part of the basic training curriculum. This means that officers trained before may be using pieces of the SFST battery or not using them at all. A proper DWI case, if field sobriety tests are being used, must include some sort of standardized elements. If not used, the officer’s determination for probable cause is clearly speculative and subjective in nature.

What does all this mean for both the defense and prosecution? That both need to ensure that the officers who are making DUI/DWI arrests are using the SFST battery in accordance with their training, as well as following the standard. The SFST battery is a perishable skill set. Consequently, it MUST be constantly used or trained to ensure its proper use in making arrest decisions based on probable cause.

The NHTSA training manual recommends that officers be re-certified every two years in the SFST battery. However, many agencies are most likely not conforming to this recommendation. Regardless of the training, for an officer to determine probable cause in an arrest for DUI/DWI they must accurately use the SFST battery as it was developed and educated. Failure to use the battery properly, or as trained, will call into question an officer’s “correct” arrest decision. Hence, it may be shown that their determination for probable cause is based on pure speculation.