DUI Attorney Logo

Pre-Arrest Screening In DUI Cases



Once the driver is out of the vehicle, the officer moves into stage three of the DUI investigation, the pre-arrest screening phase.

Horizontal Gaze Nystagmus

The officer’s first task is to administer field sobriety tests. These tests, many of which have been “standardized” by NHTSA, provide a judge or jury with objective descriptions of the clinical symptoms of impairment, and serve to reinforce the officers physical observations of the suspect during stage two of the investigation.

Officers know that a skilled defense attorney will scrutinize every detail of the tests. On cross examination the defense attorney will try to discredit the test by asserting that:

The officer will try to do everything possible to minimize the effects of such defense arguments. If feasible, the test will be conducted on the most ideal conditions. However, in the rainy Pacific Northwest, ideal conditions are not always available.

Types of Pre-Arrest Screening

The “standardized” field sobriety tests that NHTSA recommends are as follows:

Other, non-NHTSA standardized field sobriety tests include:

Following the field sobriety tests, the officer’s next task during a DUI investigation is to administer a preliminary breath test, which the police use to confirm the chemical basis for the driver’s impairment. A preliminary breath test is for investigatory purposes only.

If the officer is confronted with evidence of drug impairment, it will be necessary for an officer to seek assistance from an officer with special drug detection training, who will administer a standardized drug recognition examination of the suspect.

The arrest occurs at the conclusion of the pre-arrest screening process. If the officer decides to arrest the suspect, he must have probable cause that the driver is under the influence of alcohol or drugs.

When you are on the road and under investigation for DUI by a cop, you are on their turf. They have the power. However, when you go into court with a DUI defense attorney, and your attorney cross-examines the cop, the cop is out of his/her element. If the cop has made mistakes, a good DUI defense lawyer will make sure that the jury knows about them.