What should an officer do if they notice a subject displaying unusual behavior?

Documenting the unusual behavior of a subject is essential in the context of Standardized Field Sobriety Tests (SFST). This documentation serves multiple purposes: it creates a record that can be referenced later for evidence in court, helps support the officer's observations and judgments about the subject's condition, and may assist in identifying patterns of behavior that indicate impairment. By thoroughly documenting, the officer can provide a clear and detailed account of the subject's behavior, which can be crucial in legal proceedings or further assessments.

Seeing unusual behavior could indicate a variety of issues, including but not limited to impairment. Providing a thorough and objective account allows for a better understanding of the situation and ensures that the necessary protocols are followed professionally. The other options do not adequately address the need for careful observation and documentation, which is why they are not appropriate responses in this context.