The laws relating to Driving Under the Influence (DUI) have provided a standard formula when it comes to prosecuting defendants who have consumed too much alcohol and chose to get behind the wheel of the car. We have two ways to proceed, and we often proceed with both routes: (1) the defendant’s blood alcohol content (BAC) was above the legally allowed limit of .08% at the time of driving; or (2) the defendant was impaired at the time of driving.

This second theory relies on the objective signs of intoxication present in the defendant as observed by the investigating officer and witnesses on the scene. Bad driving, terrible field sobriety tests, and the admission of alcohol consumption are just a few of the things prosecutors rely on to show impairment.

Being under the influence as it relates to drugs (both legal AND illegal) is a much trickier concept. This is because there is no set standard provided by the law where it is presumed someone is under the influence of a drug. Science has provided us with “therapeutic levels” that can be used, but that simply means that at that particular level the drug is doing what it is supposed to be doing. When drugs are involved, we have to show that the drug caused impairment.

#13 involved a drug related DUI case. The defendant had been driving down a curvy backroad from the Town of Paradise into Oroville near the Lime Saddle Marina. He was driving too fast and failed to negotiate a curve. Witnesses in the opposite lane of traffic saw his vehicle cross a double yellow divide. They had to swerve to avoid being hit. Defendant’s vehicle then continued on, rotating 180 degrees, before falling off an embankment. Luckily the vehicle landed on a culvert pipe that was approximately 25 feet below, stopping the fall into the canyon. Defendant, and his passenger, both exited the vehicle and tried to convince the witnesses not to call police. At first, defendant claimed the passenger was the driver, but eventually admitted to driving and to drug use. Blood results showed: Soma, Valium, and marijuana in his system. All the drugs were within the therapeutic range, except the Soma which was toxic (in this situation “toxic” means above a therapeutic range).

The issue: was this bad driving because of impairment or just bad driving?

There were just too many questions the jury wanted answered by our experts in this case. For example, our officer had not been trained as Drug Recognition Expert (some officers are trained to identify individuals and what potential drugs they are under the influence of based on field sobriety tests and other factors). Because of the lack of training she did not feel qualified discussing the field sobriety tests and how they related to drug impairment, based on her training and experience. Additionally, it was impossible for our pharmacist to tell the jury what level of drug in the blood would lead to impairment. So while it was clear drugs were in the system, the jury had very little guidance on whether or not defendant was impaired by them.

Bad driving was the main indication. But it was bad driving on a dangerous road.

The strangest thing to me was that the jury, after the fact, told me some of the members felt there was a distinction between “being under the influence” and “impairment.” “Under the Influence” is a legal term which is defined by the court in a specific jury instruction given to every jury on this issue:

“A person is Under the Influence if, as a result of consuming or taking a drug, his or her mental or physical abilities are so impaired that he or she is no longer able to drive a vehicle with the caution of a sober person, using ordinary care, under similar circumstances.” (Cal. Crim. 2110)

Some of the jury members felt we had met our burden of showing the defendant was under the influence of the drug, but believed the defendant was not impaired. It took me a while to understand this distinction because impairment is embedded in the definition of “Under the Influence” itself. I think it boiled down to the fact that it was not clear in this case whether the defendant actually had a loss of function or ability that led to to the bad driving or, in the alternative, the defendant just drove badly down a winding backroad in rural Butte County.

The ambiguity in impairment is unfortunate because driving under the influence of drugs is just as dangerous to the public as those who choose to do so with alcohol in their system. It is just more difficult to prove beyond a reasonable doubt. Until we can provide clarity as to what levels we can presume impairment in drug cases, much like we do with the .08% standard for alcohol consumption, this jury struggle will continue.