How Can A Prosecutor Prove I was Driving Impaired by Prescription Drugs?

Presence of the Drug does not Equal Impairment

At first glance, the question that constitutes the title of this post may seem like a question with a simple answer, but it’s not.  When one really looks at the question in the context of a driving under the influence of prescription drugs case in Southern Utah, one quickly realizes that it becomes a complex issue.

First, you have to look at the law in Utah as it is today as it relates to driving under the influence of prescribed pharmaceuticals, which is much more narrow than driving under the influence of alcohol.  With alcohol, all the prosecutor has to show that the blood alcohol content of the driver was .08 or greater.  With pharmaceuticals, if you have a prescription a prosecutor must prove beyond a reasonable doubt that you were under the influence of that drug “to a degree that renders [you] incapable of safely operating a vehicle.”

In order to prove such impairment the prosecutor must first establish that the drug was in the person’s system.  This is accomplished through blood work which will show either positive or negative for a pharmaceutical drug.  The problem with blood work, however, is that it cannot show how much of the drug was in the blood system at the time of driving or at the time of the test.  Even if it could show how much of the drug was in the defendant’s system, that does not necessarily show that the person was impaired as a result of the drug; it merely proves that the drug was in the body.

Prosecutors argue that mere presence, coupled with how a person performs on field sobriety tests, the defendant’s behavior, and driving pattern is enough for a jury to conclude that the drugs caused the impairment.  That reasoning, however, does not flow logically, because there could be a million other reasons for the defendant’s behavior, driving pattern, and performance on field sobriety tests.  For example, people take prescribed drugs because they have something wrong with them.  The cause of the illness can often times be the cause of the defendant’s behavior.  Diabetes, neuropathy, sleep disorders, and other physical disabilities can all cause was can be perceived as “impaired driving.”

In these types of cases defendants and their attorneys have to present their case in a way that forces the jury to understand the inability of the prosecutor to prove impairment.  That’s what we do.  Call us for more information.