When a police officer stops a person, there needs to be some reasonable suspicion for detaining (stopping) the person. Usually, an officer will observe a violation of the California Vehicle Code, which the officer must be able to specifically articulate (explain) in order to justify the stop. In some cases, the basis for stopping a driver can be something as minor as a burnt-out taillight or observing expired registration tags, whereas in other cases it can be more complex, such as observing the driver responding “slowly” to traffic signals. Unfortunately, because cars and motorcycles are heavily regulated by the government, the law gives quite a bit of flexibility to police officers in order to pull a person over for virtually any Vehicle Code violation. In many cases, a person can be stopped for a simple traffic violation, where the officer has no idea that the person may be DUI. Then, once the officer interacts with the driver, what was originally a traffic stop can now become a criminal investigation for DUI. In order for the officer to be allowed to continue detaining (holding) the driver for DUI, the officer must be able to continuously articulate more and more evidence justifying the officer’s suspicion of DUI in order to be legally allowed to continue the investigation.
In many cases, a police officer will pull a driver over for something such as speeding. Once there is further contact with the driver, the officer may then for example observe red and bloodshot eyes, hear slurred speech, and smell the odor of an alcoholic beverage coming from the driver’s breath. If the person is asked to perform some Field Sobriety Tests (FSTs), the officer may for example observe the unsteadiness of the driver. In some instances, these observations can be further evidence of DUI, but in many cases, the observations are easily explainable by another reason unrelated to DUI or greatly embellished by the officer. As a general overview, the three phases of a DUI investigation require a police officer to observe the vehicle in motion, then have personal contact with the driver, followed by pre-arrest screening questions. DUI investigations are highly standardized and in order for the arrest to be legally valid, police officers are required to precisely follow the same investigation method each time. From experience, most police officers are not aware of the precise method and standardized rules to be followed, and this leads to many cases being dismissed or greatly reduced.