The preliminary alcohol screening device, also known as the PAS, is a handheld device used to detect alcohol in the blood in a San Diego DUI case. This is one of the standard field sobriety tests (FSTs) that are used when someone is detained due to suspicion of driving under the influence of alcohol (DUI). Officers use this test, among others, to determine whether to arrest someone for driving under the influence. The PAS test is usually the final field sobriety test (roadside test) before the officer makes the decision whether or not to arrest.
