| Investigation of DUI Cases: | | | | The HGN in combination with the WAT reflects an |
| What are the SFST's? | | | | 80% accuracy rate in determining a BAC above .10%. |
| How do CA courts deal with FST's that are not | | | | The WAT and the OLS are "divided attention" tests. |
| performed in accordance with NHTSA? | | | | Divided attention tests require a subject to listen to and |
| The National Highway Traffic and Safety | | | | follow instructions while performing simple physical |
| Administration (NHTSA) has done extensive studies of | | | | movements. Sober individuals are supposed to |
| field sobriety testing (FST's) in order to determine the | | | | perform these tests with no problem. Impaired |
| probability of intoxication. Law enforcement agencies | | | | individuals, however, have difficulty with tasks requiring |
| have utilized FST's for many years to develop | | | | their attention to be divided between simple mental and |
| probable cause for arrest and as evidence to be used | | | | physical exercises. |
| in the prosecution for drunk driving. However, not all | | | | As mentioned above, law enforcement agencies |
| FST's have been scientifically determined to be | | | | utilize FST's in addition to SFST's. The SFST's have an |
| accurate reflectors of alcohol intoxication. NHTSA has | | | | advantage in that they have scientific backing. |
| determined that three FST's are accurate indicators of | | | | However, FST's do not have such scientific data to |
| alcohol intoxication, when administered in a | | | | support the conclusion that the drunk driving subject is |
| standardized manner. These tests are called | | | | intoxicated. Examples of FST's include: the Rhomberg |
| Standardized Field Sobriety Tests (SFST's): | | | | Balancing Test, Finger to Nose, Alphabet Test, Count |
| 1. Horizontal Gaze Nystagmus (HGN). HGN is an eye | | | | Down, and Hand Pat, among many others. |
| test that is 77% accurate in reflecting a blood alcohol | | | | Even though the FST's do not have scientific backing |
| count (BAC) above .10%. Nystagmus is an involuntary | | | | reflecting reliability, most courts will still admit the tests |
| jerking of the eyes at a certain angle, off to the side. | | | | into evidence. In California, courts allow all FST's into |
| 2. Walk-and-Turn (WAT). WAT is a walking test that | | | | evidence, but defense counsel can attack the weight |
| is 68% accurate in reflecting a BAC above .10%. | | | | of the evidence by challenging the reliability of the |
| 3. One-Leg Stand (OLS). OLS is a test done in a | | | | non-standardized tests. Other states only allow the |
| stationary position that is 65% accurate in reflecting a | | | | actual SFST's into evidence. |
| BAC above .10%. | | | | |