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New York Times investigation finds breathalyzer tests unreliable

On Behalf of | Nov 11, 2019 | Drunk Driving |

About a million people each year are arrested for drunk driving in the United States. When you’re pulled over on suspicion of OWI, you will be asked to blow into a breathalyzer.

These tests are used by virtually every police department in the nation, but there could be problems with their accuracy, the New York Times found in a major new investigation. The machines need precise calibration before they can even be used, but many police departments lack the expertise or interest in maintaining proper calibration. And when they’re not properly calibrated, they tend to overestimate the amount of alcohol in a person’s breath.

If the Times is right, this is a big problem. While roadside breath tests are often inadmissible on their own, they are used to provide probable cause for a more precise test. Furthermore, if you refuse to take the test, you lose your license.

42,000 convictions could be overturned in just two states

In Massachusetts, a series of mistakes and instances of misconduct left the state’s breathalyzers improperly calibrated. Ultimately, a court decided that eight years’ worth of breath tests were untrustworthy and inadmissible as evidence. That translated to at least 36,000 convictions where the main evidence was tossed out. Defense lawyers are scrambling to notify affected defendants.

In New Jersey, an unknown number of breath testing machines were never set up correctly in the first place. Over 13,000 people have been convicted based on the faulty test results.

Those two states are not unique. The Times investigation found problems with breath testing machines in multiple states and pointed to the potential that these problems could exist anywhere.

The exact problems with breathalyzers depend on the brand of the machine being used. Here in Iowa, we use the DataMaster CDM and the DataMaster DMT. Last year, a judge in Minnesota found that these machines appeared to be rounding up the results, making people appear more drunk than they actually were. That ruling is under challenge, but the Times also found that Minnesota had turned off a quality-control portion of its DataMasters entirely because the component kept breaking.

Defense rarely gets to challenge the accuracy of the machines

Another issue pointed out by the Times is that breath testing machines contain proprietary information and trade secrets that their manufacturers seek to protect. In practice, this has meant that defense attorneys are typically not allowed to examine the machine and its programming to determine how it works. Without knowing how it works, it’s difficult to know if it worked correctly.

Are people being convicted based on exaggerated breathalyzer tests? It seems certain that they are. How can we call this justice?



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