ABSTRACT
In this chapter, cases are presented where the police have used breathalyzer instruments to determine a defendant’s BAC. When a police o°cer stops a person on suspicion of DUI, he uses several techniques to determine if the person is intoxicated. He uses ˆeld sobriety tests or a preliminary breath test (PBT). PBT test instrument is a hand-held device into which the suspect is asked to blow air. e instrument gives a reading aªer measuring the alcohol in the breath and extrapolates it to BAC. ese tests are not admissible in courts of law in several states in the United States. Nevertheless, this gives an idea to the police o°cer if further tests are warranted to asses a defendant’s level of intoxication. He can take a suspect to the police station and subject the suspect to an approved breathalyzer instrument. Cases involving the use of dierent breathalyzer instruments are given.