As previously discussed, officers are trained in three different Phases of Driving While Intoxicated detection. Phase 1 involves the officer’s observations of the vehicle in motion, Phase 2 involves the officer’s personal contact with the driver and Phase 3, which I will discuss here, involves Pre-Arrest Screening.
During Phase 3, the officer will determine whether the driver has consumed alcohol and whether such consumption has impaired the driver to the extent that he should be arrested. The main focus during Phase 3 is on the driver’s performance on the Standardized Field Sobriety Tests (SFSTs). During this Phase the officer might also ask the driver to blow into a Portable Breath Test (PBT) to determine the presence of alcohol but the PBT should only be used to support the SFST; it should not be used in place of SFSTs. In New York, the results of a PBT are not admissible at trial (but they are admissible at pre-trial hearings).
The SFSTs not only determine impairment but also whether the driver can perform divided attention tasks. The only three SFSTs validated by the National Highway Traffic Safety Administration (NHTSA) are the (1) Walk-and-Turn; (2) One-Leg-Stand; and (3) Horizontal Gaze Nystagmus. These will all be discussed separately in future blogs.
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