Jun 10, 2010 Why judges should keep out breath test results in the absence of testimony of the person calibrating the machine
Image from National Institute of Standards & Technology.
Earlier this year, I blogged about Washington, D.C.’s breathalyzer machine debacle.
This week, D.C. officials admitted that almost 400 people were convicted with the inaccurate machines. Worse, half of them went to jail, usually for at least five days, as reported by the Washington Post today.
D.C. Attorney General Peter Nickles said that the Metropolitan Police Department’s breath testing machines were mis-calibrated by twenty percent by the officer maintaining the machines. This means, for instance, that instead of showing a blood alcohol level of 0.07 (which is below the 0.08 legal limit), the machine would show a result of at least 0.084.
Breath testing machines are fraught with inaccuracy risks, and must be meticulously maintained, repaired and recertified (being machines, they will wear down). They should only be used -— if at all -— to screen whether to take a blood test, which is much more accurate than breath testing, when done properly. This is akin to dipstick tests for drugs in urine. If the dipstick does not change color in the urine, that is a passing test. If the dipstick changes color, the urine needs to be sent to a lab for a proper analysis.
When judges are skeptical about my insistence that breath test results not be admitted into evidence without the testimony of the person who calibrates the machinery, I can include this Washington Post article among the arguments supporting my position. This debacle in Washington, D.C., is doubtfully limited to D.C. itself. The debacle results from human error (if not from human malice or laziness, as well) that can happen anywhere, and that has already harmed hundreds of lives (at the very lease) of defendants wrongfully accused with faulty breathalyzer tests.