What type of evidence is primarily used in DWI investigations?

In DWI investigations, sensory evidence plays a crucial role in establishing the observed behavior and condition of the suspect. This type of evidence is based on the observations made by law enforcement officers regarding indicators of impairment, such as the suspect's physical appearance, motor skills, speech patterns, and odor of alcohol. Officers are trained to look for specific signs of impairment when interacting with drivers suspected of driving while intoxicated, and these sensory observations often form the foundation for further investigative actions, including the administration of Standardized Field Sobriety Tests (SFSTs).

Sensory evidence is critical because it provides immediate, first-hand accounts of a suspect’s behavior and condition, which can influence an officer’s decision on whether to conduct additional tests or make an arrest. The validity of sensory observations is often corroborated through the subsequent results of field sobriety tests or chemical tests, but the initial observations are key to the investigation process. Thus, sensory evidence remains the primary type of evidence utilized in DWI cases.