Most Texans are likely aware of the many states that have legalized marijuana for medical or recreational use. The legalization of marijuana in those states has led to questions about how to properly test for it when a person is driving.
While research and a body of law backing up testing for alcohol impairment levels exist, marijuana affects every person differently. This means that there is not one single amount that can be said to reliably impair an individual's driving. Another issue is that tests look for metabolites that are present in a person's blood or urine. With marijuana, metabolites can be present for several weeks after a person ingests it, meaning that tests may show metabolites when the person is not impaired at all.
Researchers are working to design tests that can be used for marijuana. One company in California has developed a test that can detect marijuana on the breath. While the company says that it needs to be tested before it can be marketed, there is still no understanding of what level of marijuana in the system is impairing to drivers or how to account for the presence of metabolites in the system when the person could have smoked weeks before.
Texas residents who are facing DWI charges for marijuana might want to get help from an experienced criminal defense attorney. Legal counsel might be able to file motions in order to try to keep out any testing that was performed. The attorney may also review the reason for the stop to make certain that it was conducted in a constitutional manner. If it wasn't, the attorney may file a motion seeking suppression of the evidence.