A “driving under the influence” arrest can mean a multitude of things. Most commonly people tend to associate it with driving while being under the influence of alcohol. However, it could mean under the influence of any controlled substance.
In order to prove the influence of drugs, the arresting officer looks for common markers. The first judge is often erratic driving, this is what causes the accused to be pulled over in the first place. The second marker looked at is the physical appearance and conduct of the accused. Simply stated does he or she look like they have just used drugs. The officer will also look to how the accused is acting whether or not they seem nervous or agitated. The third thing an officer will do if they suspect the accused is under the influence, is administer field sobriety tests. These can include a variety of things. According to DUI Central: “The most common are; walk-and-run, one-leg-stand, eye follow the officer’s finger, modified position of attention test, touching finger-to-nose, reciting the alphabet, rapidly touching four fingers to the thumb, and the rapidly alternating hand pat.”
Based on all of these factors, the arresting officer could conclude a blood test or a urine test is in order. While testing the blood or urine, the doctor is looking for specific metabolites, or chemical compounds, profiled to common narcotics. The problem with this method of discovery is that the drug need not be active to have a metabolite show up on test. In layman’s terms, the accused could have gone to a party the day before and smoked some marijuana yet it would still show up on the test as if he or she had just smoked it.
When fighting a DUI case, the accused, with the right attorney, could potentially have a lot of ground to stand on. First off even with a positive urine or blood test, the accused could claim that he or she was not under the influence at the time of arrest. Since the court is only focused on whether the accused was driving while under the influence, not whether or not the accused uses drugs, it becomes harder for the prosecution in charge. Secondly, although science can prove the drug was in the person’s system, science is still unable to identify how much of the metabolite is needed in the sample before impairment happens. Also science cannot determine how much of a tolerance the accused has built up to the particular drug.