An in-depth investigation by the New York Times finds one of the most common tests used by law enforcement to determine whether someone is driving drunk produces false positives with alarming frequency.

Nearly every police station across the country uses breath test devices, which are routinely marketed as being accurate to within 0.001%. However, the Times reports instances where the highly-sensitive instruments yielded results that were up to 40% too high.

Colorado case uncovers quality control issues

Officers in Colorado have used the Intoxilyzer 9000 series machines for the past several years when implementing breath tests for those suspected of DUI. According to the Times, Robert Friedlander was pulled over by officers in May 2016, and his blood alcohol concentration (BAC) level measured 0.07%, which is below the level considered drunk, but still high enough to be charged with impaired driving.

Friedlander had been convicted of the same crime years before and had carried around a small portable breath test unit ever since. On the night he was arrested in 2016, he had tested himself an hour earlier and registered a BAC of 0.05%, so he waited one hour before driving. His case set off a firestorm over widespread problems that the state forensic lab had getting the machines ready.

Judge tosses breath test results

During Friedlander’s trial, it was revealed the forensic lab did not properly calibrate the machines as officials were in a rush to put the 160 new devices into use. It was also discovered that the lab produced false records showing that the Intoxilyzer 9000s had been properly calibrated.

The judge threw out the breath test evidence in Friedlander’s case, and he instead plead guilty to a lesser charge of reckless driving. However, the result called into question the machine’s reliability, and challenges in dozens of other cases also led to breath test results not being admitted into evidence.

Seek knowledgeable legal defense for DUI

The Times report says more than 30,000 breath tests have been thrown out by judges in New Jersey and Massachusetts in the past year alone. If you are charged with drunk or impaired driving, an experienced DUI defense attorney here in Colorado will protect your rights and aggressively challenge breath test evidence as well as field sobriety and chemical testing results.