What are the two major evidence gathering tasks of phase three?

In phase three of the Standardized Field Sobriety Testing process, the primary focus is on gathering significant evidence to establish impairment due to alcohol or other substances. The correct choice emphasizes the administration of three scientifically validated Standardized Field Sobriety Tests (SFSTs) and the use of a preliminary breath test (PBT) to confirm impairment.

The three SFSTs—Horizontal Gaze Nystagmus, Walk-and-Turn, and One-Leg Stand—are designed to be reliable indicators of a person's level of impairment and are backed by research validating their effectiveness. Administering these tests helps law enforcement officers systematically evaluate the physical and cognitive functions of the individual suspected of driving under the influence.

Furthermore, the addition of the PBT serves as an additional layer of evidence. It provides an objective measurement of a driver's blood alcohol content (BAC) at the time of the stop, which can support the signs of impairment observed during the field sobriety tests.

This combination effectively enhances the strength of the evidence needed to make informed decisions regarding possible arrest and further testing, ensuring that law enforcement actions are justified and legally sound. The other choices might not provide a complete or valid approach to gathering evidence effectively in this context.