Driving Under The Influence: Proving DUI

The National Highway and Traffic Administration reports 10,076 people died in drunk driving crashes in 2013. It is no wonder that those convicted of DUI face many harsh penalties. However, in order to be convicted of DUI, a defendant must either plead no contest or guilty, or force a prosecutor to prove their case beyond a reasonable doubt to a jury.

There are several parts to a jury trial. The trial begins with jury selection and ends with closing arguments. During jury selection, both the prosecutor and the defense attorney have the opportunity to ask the jury panel, several questions to determine who would make good jurors for their case. This panel gets narrowed down to six people who become the jurors. After jury selection, the prosecutor gives his opening statement. The prosecutor’s opening statement lets the jury know what they can expect to hear from the witnesses’ testimony. The defense attorney then proceeds with his or her opening statement. The prosecutor then calls all of his or her witnesses, and the defense attorney has the opportunity to cross-examine these witnesses by asking leading questions. The defendant may or may not have witnesses to testify. The defendant has the choice to testify or not to testify.

In many DUI cases, the arresting officer is the prosecutor’s only witness. The prosecutor’s job is to elicit facts from the officer to prove his case. In a DUI case, the prosecutor must prove two elements beyond a reasonable doubt. First, the prosecutor must prove beyond a reasonable doubt that the Defendant was either operating, or in actual physical control of a motor vehicle. The prosecutor usually has no difficulty proving that the Defendant operated the motor vehicle. The police officer simply identifies the Defendant as the driver. Second, the prosecutor must prove that the defendant either had a blood alcohol level of .08 or more grams of alcohol per 100 milliliters of blood, or a breath-alcohol level of .08 or more grams of alcohol per 210 liters of breath. Alternatively, if the Defendant refuses to give a breath sample or urine sample (in the case of suspected drug use), then the State must show that the Defendant was under the influence of alcohol, a chemical substance or a controlled substance to the extent that his or her normal faculties were impaired. Normal faculties include, but are not limited to the ability to see, hear, walk, talk, judge distances, drive an automobile, make judgements, act in emergencies and, in general to perform the many mental and physical acts of our daily lives.

Prosecutors use the officer’s testimony to show that the Defendant’s normal faculties were impaired. The officer may testify that Defendant was swerving, to show that his ability to drive an automobile was impaired. Additionally, the officer may testify that while administering the field sobriety exercises, the Defendant couldn’t walk a straight line, or lost his balance, to show that his ability to walk was impaired. Furthermore, in the case of a breath refusal, the prosecutor will argue that the Defendant refused the breathalyzer because the Defendant knew he was over the limit. The prosecutor argues what is known as consciousness of guilt; the Defendant refused to blow because he knew he was under the influence. The defense can rebut this argument by explaining to a jury that there are other reasons (other than guilt) why a Defendant would choose not to give a breath sample. The Defendant may not trust the breathalyzer to give an accurate reading. He or she may have been treated unfairly by the police officer and is now unwilling to cooperate. Finally, the defendant has already been placed under arrest, and is not free to leave.