How can the prosecutor prove I was driving drunk?
If you’ve been arrested for DUI, you are right to be concerned about the potential consequences. Loss of your driver’s license, jail time, fines and assessments, insurance surcharges, installation (at your cost) of an ignition interlock device, and other penalties are all potentially in your future if you are convicted, even if it’s a misdemeanor, and even if it’s your first DUI.
But just how does a prosecutor go about proving that you were under the influence of alcohol? The answer is that evidence in your case could come from one or more different areas. Some of the more common ways to prove a DUI are:
- Blood alcohol content. Your blood alcohol content (BAC) is an extremely important aspect of a drunk driving case. In fact, the law in Arizona says that if your BAC is 0.08 or higher, even without any additional evidence of intoxication, you can be found guilty of driving (or being in actual physical control) while under the influence. BAC can be measured indirectly through a breath test, or directly through a blood test. In either case, a BAC over the legal limit (0.08 or higher) is evidence that you are guilty under the statute.
- Standard field sobriety tests (SFST). You’ve probably heard on the news or read newspaper or internet accounts of DUI arrests, where the story includes a statement to the effect that the suspect “failed” a sobriety test. There are many so-called field sobriety tests, but only three, known collectively as the SFST, have been sanctioned by the NHTSA, the federal agency charged with enforcing vehicle safety standards. They consist of a test of involuntary eye movement known as Horizontal Gaze Nystagmus; the walk and turn; and a test involving balancing on one leg while counting out loud. When an officer claims that you failed one or more of these tests, it is a conclusion based upon that officer’s subjective view of how you performed. Nevertheless, it can provide evidence that you were under the influence of alcohol.
- Appearance and demeanor. How you look, what you do, and even what you smell like can provide evidence of intoxication. The smell of alcohol (typically stated by the police as the “strong” smell of alcohol), could lead to a conclusion that you have been drinking. While it does not provide an answer to the question of how much you drank, or when you drank it, testimony that you smelled of gin can certainly hurt your defense. Similarly, if you stagger when getting out of your car, or slur your words, that may be used as evidence that you were under the influence. And bloodshot eyes, a disheveled appearance, and other physical signs can also be used against you.
- When you don’t keep quiet. You might be surprised at how many people are convicted of crimes, including DUI, based partly, or even primarily, on statements they have made to the police. Here is where you have the ability to make things worse, or not. If you tell the officers that you’ve just left Joe’s bar after drinking for several hours, you might get points for honesty. On the other hand, you are not required to speak to the police officers. If you choose to do so anyway, you run the risk of providing damaging evidence against yourself in your case, even when you truly believe you are not under the influence of alcohol.
- Witness testimony. Evidence in your case can also be obtained through the testimony of witnesses. They might, for example, include the bartender or servers at a restaurant or bar, another driver who says your vehicle was swerving from lane to lane, or even a passenger in your own vehicle.
These are just some of the ways in which evidence can emerge in a DUI case. Remember, however, that the right DUI attorney can often challenge such evidence – BAC readings, SFST results, and others – and ultimately, the question is whether, when all the evidence in your case is considered, it appears to the jury (or the judge, in a bench (non-jury) trial, that the prosecution has proven every element of the case, beyond a reasonable doubt. If not, the verdict is NOT GUILTY!