Despite what many other states have done in recent years, Texas continues to make the possession of cannabis illegal. It is also against the law to drive a motor vehicle while under the influence of marijuana and other drugs.
Before arresting someone for driving while impaired, officers must have probable cause. For drunk driving, a failed field sobriety test may give officers probable cause to believe a driver is under the influence of alcohol. If the results of a recent study are true, that may not be the case for marijuana intoxication.
Field sobriety tests
The NIJ, the agency inside the U.S. Department of Justice that performs research, conducted a study to determine whether performance on field sobriety tests was a reliable indicator of marijuana intoxication. The study determined it is not.
THC is the active ingredient in marijuana. While a person’s blood alcohol concentration is a good indicator of alcohol intoxication, the NIJ study found THC levels in a person’s system did not positively correlate to marijuana intoxication.
Because the NIJ study is new, it is not yet certain how it may affect the way officers develop probable cause to support an arrest of a suspect for driving while impaired by marijuana. If a person is facing DWI charges, though, the study should provide some encouraging and potentially useful news.
Prosecutors typically must prove all elements of an offense beyond a reasonable doubt. Ultimately, those who are defending themselves against charges of drugged driving may be able to use the NIJ study to cast doubt on their guilt.