Illinois DUI law provides that it is illegal to operate a motorized vehicle on the public roadways if the driver is in actual physical control of the vehicle while under the influence. 625 ILCS 5/11-501 Evidence of driving under the influence consists of general observations, such as poor driving, the interaction with the officer while the driver is still seated (eyes that are bloodshot, an odor of alcohol from the breath, slurred speech, difficulty locating insurance card, drivers’ license and registration) and the vehicle exit process, including any stumbling, staggering or balance difficulty.
The police also employ specific “divided activity” tests known as the Standardized Field Sobriety Tests (SFST). This sequence of activities, which includes the HGN, the walk and turn and the one legged stand, requires the subject to perform multiple tasks simultaneously. For instance, during the one legged stand, the test taker must hold his leg off the ground six inches, while also looking at the elevated foot and counting from 1 to 30.
The driver will then be asked to submit to a Preliminary Breath Test (PBT). The PBT is a device that is not certified for accuracy the Illinois State Police or subject to any legally recognized regulations. After a user blows into a tube, the PBT device generates a number that estimates the driver’s blood alcohol level (BAL).
The results of the PBT are not admissible in the DUI prosecution itself as evidence of the driver’s BAL. However the arresting officer is authorized to use a BAL of .08 or greater on the PBT in reaching an arrest determination. 625 ILCS 5/11-501.5
After gathering all this information, the officer arrests you for DUI, following which you will be asked to submit to another type of test, either blood or breath, to determine your BAL. These results are gathered using a more precise method and unlike the PBT results, they can be used in the DUI case to prove your BAL. In addition, if you elect not to submit to these tests, your “refusal” can be disclosed to the jury as evidence of a “guilty mind”. People v. Rose, 268 Ill. App. 3d 174, 178, 643 N.E.2d 865, 868 (1994)