Section 71 Manipulation of Breath Test—Police Officer Instruction Can Vary Result and Conflict With Department of Health and Senior Services “Methods and Techniques”

• Library: DWI Experts and the Science of Chemical Tests 2014

How the officer tells the subject to blow into the machine can have a dramatic effect on the result. In Raisher v. Director of Revenue, 276 S.W.3d 362 (Mo. App. W.D. 2009), the MSHP officer had the subject blow into the machine, and the result came back 0.078% (below the legal presumptive level). The officer then had the subject blow another way, and the next test was 0.094%. This difference of just 0.016% put the subject over 0.08%. This manipulation of test results from one under the legal limit to one over the legal limit by the blowing instructions given to a subject by the police officer giving the test is very troubling. Raisher shows how test results in close cases can be manipulated by the officer.

This is not just a Missouri problem. In State v. Briggs, No. 2006‑CT‑2638 (Fla. 2^nd Judicial Cir. Aug. 20, 2007), the officer was found to have manipulated the result on an Intoxilyzer...