The February issue of the Illinois Bar Journal carries my article on “How to Admit or Exclude PBT Results” [Subscription Req.] . PBTs are preliminary breath tests that are typically administered by the police on the scene of a traffic stop. The police use the results of a PBT as a factor to help establish probable cause to arrest a driver for driving under the influence of alcohol. PBTs are different and less reliable than the breath tests typically given at the police station—a.k.a. chemical tests—and therefore PBT results are treated differently than chemical test results. The article explains (1) when PBT results are admissible in court, (2) when the State is required to lay a foundation for their admission, and (3) what constitutes an adequate foundation.
This article arose out of my work as a staff attorney at the Eighteenth Judicial Circuit Court of Illinois. However, the views express in the article are mine and not necessarily those of the Eighteenth Circuit.
 Eric R. Waltmire, How to Admit or Exclude PBT Results, 96 Ill.B.J. 92 (2008).