Recent articles in the New York Times have raised questions about the reliability of breath testing devices used across the country in DUI cases. These Machines Can Put You in Jail. Don’t Trust Them and 5 Reasons to Question Alcohol Breath Tests. The authors also interviewed a defense lawyer and defense expert in NPR, and heard from other persons connected with the breath testing process including an officer and a defendant. Blown Away: Why Police Rely On Faulty Breathalyzers.
Breath testing is used to estimate a level of alcohol in the person’s blood. Breath testing relies on an assumption that a persons breath can contain alcohol in roughly a 1/2100 ratio of the alcohol in the breath to the alcohol in the blood. There are numerous other assumptions as well, highlighted in an article by Leonard R. Stamm, and published in the magazine of the National Association of Criminal Defense Lawyers, the Champion, titled The Top 20 Myths of Breath, Blood and Urine Testing.
The New York Times articles highlight some of the problems that have plagued the government’s efforts to prosecute drunk driving cases. This includes problems with calibration, maintenance of the machines (officers insist on calling them “instruments”), the controls that are used, the adequacy of the procedures used to test individuals, failures in record keeping, secrecy in computer codes, human errors and others.