Alcohol consumption is not necessary for a person to be arrested and convicted of driving under the influence, says Broward DUI Lawyer William Moore. Alcohol is easier to quantify through the use of a breath test. Although urinalysis can detect the presence of drugs, the test does not show the amount that was present in a person’s system at the time of the test. Only a blood test quantifies the amount.
In cases where a blood test was actually obtained, the results will usually be interpreted by a toxicologist, who will be called by the state to testify regarding the substances actually present as well as the amount of the drugs present. For example, just knowing that a driver had a breath test of 0.02 — well under the per se limit of 0.08 at which the law presumes a driver to be too impaired to operate a motor vehicle — combined with the presence of Xanax in the body is insufficient to prove a DUI. However, if a toxicologist is present with the results of a blood test, that information can be key for a jury to make a decision regarding a person’s guilt. If the Xanax was at therapeutic levels, or the level generally prescribed by a physician, the person is less likely to be found guilty of driving under the influence. If, however, the levels are several times higher than the therapeutic dose, the case is more difficult. This is particularly true where the blood test results conflict with statements made by the defendant following his arrest regarding how much Xanax he took.
Generally, the police will also need a reason to request testing beyond a breathalyzer. For a urine test, there must be probable cause to believe that the person has drugs in his or her system. Blood draws are more complicated. The first reason a police officer can require a blood draw, even forcible, is following an accident with a fatality or where there were serious bodily injuries. The second would be where it is impractical to use a breath test, such as a driver who is unconscious or is being treated in a hospital. The third way for a blood draw to come about is if the driver consents to it, after being informed that it is an alternative to a breath test. Drivers do not have a choice of test, even though there is evidence that blood tests are more accurate than the breathalyzer machine, notes Fort Lauderdale DUI Lawyer William Moore.