How can officers identify impairment due to drugs or alcohol, and what standardized tests apply?

• A. Test only when suspicion is high but not using SFST
• B. Use blood tests for all
• C. Observe impairment signs; administer Standardized Field Sobriety Tests (SFST) and consult drug-recognition if applicable; follow implied-consent laws
• D. Rely on appearance alone

Answer: (C)

Identifying impairment from drugs or alcohol in the field relies on combining observable signs with standardized testing and the legal authority to compel a chemical test. Officers first observe and document cues such as slurred speech, slowed reaction, poor coordination, abnormal behavior, and odor. When impairment is suspected, they administer standardized field sobriety tests—the horizontal gaze nystagmus test, the walk-and-turn test, and the one-leg stand—that are validated protocols. Properly trained officers administer and score these tests to help establish probable cause for a chemical test. If impairment from drugs is suspected, a Drug Recognition Expert (DRE) evaluation may be used to assess and identify possible drug categories through a structured 12-step process. Finally, officers follow implied-consent laws, which require performing a chemical test (breath, blood, or urine) after probable cause is established, with the method and consequences governed by state law. Relying on appearance alone is not reliable, and chemical testing is not automatically required in every case—the SFSTs provide a standardized, objective basis for moving forward to testing.