Breath Tests Are Inaccurate.

I have been saying this for years, as has anyone who works in the system. Now the NY Times has written an expose on the intrinsic problems, software and hardware, with breath testing machines. The full article is here.  The study was done in conjunction with the FX show The Weekly and was broadcast 11/3 under the title “Guilty By Machine”.

In Massachusetts, Washington and New Jersey, among other states, criminal defense attorneys were able to get an inside look at breath testing machines and their experts determined that the machines are improperly calibrated, were set up improperly and software errors caused the machines to give faulty results. These faulty results were then used by cops and prosecutors to arrest and convict innocent people of DUIs.

Massachusetts threw out 36,000 breath tests. The prosecutor had to send the people who had been convicted letters letting them know that. In D.C. over 350 cases had to be reopened because they relied on bad test results, there were another 700 with questionable tests that the prosecutors felt did solely rely on those tests where the test takers did not get letters. In Colorado people without any technical experience were used to set up the machines and they forged the signature of a person after he had left on documentation that it was properly set up. California DUI defense attorneys’ efforts to obtain the software and peak behind the scenes of the machines has largely been thwarted by the cops, prosecutors and the courts.

The article didn’t talk about breath testing machines in California, but California jurisdictions all use the same type of machines used in the states where the results were thrown out.  The science is basically the same: you either have an infrared or electric based measurement of alcohol. In addition to the specific problems with the machines alluded to in the article. The machines are not specific to ethyl alcohol and can increase their readings based on other chemicals in the breath. The machines can also be skewed because of alcohol in the mouth (the machines are supposed to read only the alcohol in the lungs). As the former owner of one of the breath testing manufacturer’s stated, “The tests were never meant to be used that way,” said John Fusco.

Anecdotely, a friend used to tell the story of how when he went to the manufacturer’s class on operation of their machines, they gave a ‘wet’ lab which is an excuse to drink alcohol and blow into the machines. He did so and blew long and gently the first time, then 2 minutes later he blew fast and furiously. The results of the two blows were off by double digits.

The machines don’t work as advertised. That people plead guilty to DUI or people on DUI juries naively convict people based on the readings of these machines is a travesty of justice.

The article is worth reading in its entirety by everyone who has suffered a DUI, is fighting a DUI or who may sit on a DUI jury to dispel the myth of police/government infallibility. If you have a question about breath testing please give me a call at 213-893-8640 to discuss the matter more fully.


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