Although both alcohol and marijuana may be the basis for a drunk driving arrest, they are very different offenses. An investigation for driving under the influence of marijuana is different than an investigation for driving under the influence of alcohol. If a person is charged with DUI in California, they should be aware that errors in the police investigation may help them defend against charges.

There are several ways that the police may make an error in conducting a impaired driving marijuana investigation. First, the same constitutional rights apply to marijuana investigations that apply to all other cases. The police may only stop a vehicle if they have a reasonable suspicion that the driver is violating a law. They cannot stop a person just because of the kind of vehicle that they drive or the way that they look. The police must have reasonable suspicion before they stop a driver to investigate for DUI.

Second, the police may not make the assumption that the same DUI alcohol investigation process also works for marijuana cases. Standardized field sobriety tests are verified for use in alcohol investigations. They are not approved for marijuana investigations.

If a police officer gives a driver roadside field sobriety tests, the tests may not accurately provide indicators of marijuana intoxication. In addition, preliminary breath test results as well as breath tests that investigators give at the police station are not approved tests for marijuana use. Although scientists claim that development is progressing, saliva tests for marijuana are not yet reliable.

There are many defenses that may be appropriate for a DUI marijuana case. Constitutional violations, errors in observation, mistakes and poor police training might all be valid defenses. Fighting DUI charges requires examining and asserting all possible defenses. A lawyer may help explain a defendant’s rights and assert them in court.