Thousands of arrests are being thrown out over unreliable Breathalyzer results

The Breathalyzer has become a necessary staple of DUI enforcement, but analyses have shown time and again that this equipment is unreliable, prompting some states to consider their results inadmissible. A new exposé by The New York Times reveals just how little transparency and consistency there is in the world of portable DUI blood-alcohol testing.

The Times' report identifies secretive manufacturers trying to protect their intellectual property, police departments that have become dependent on technological conveniences, and understaffed and underfunded labs cutting corners under unrealistic time and budget constraints.

There's no single cause of Breathalyzer unreliability. In some cases, inherent flaws within the machines or their programming go ignored or unaddressed. In others, the hardware is never properly calibrated in the first place. These issues are compounded by the fact that state and local governments have little incentive to pressure Breathalyzer manufacturers to submit their products for public scrutiny, as it could jeopardize ongoing and closed cases.

In one particular case, two programmers were tasked with evaluating the software that powers an Alcotest machine sold by Dräger. The Times describes a security environment that would put some high-profile commercial and government procedures to shame. When the programmers found enough flaws to conclude the device was "not a sophisticated scientific measurement instrument," the manufacturer ordered the programmers' report withdrawn. To make matters worse, in some instances like this, manufacturers have issued software fixes to correct errors in their breathalyzers, only to have state labs fail to perform the necessary updates.

In other cases, local departments simply opt out of features that can make the equipment more reliable, such as a sensor that helps the breathalyzer correct for body temperature when calculating its results. In another instance, at least one department simply disabled a component that similarly improved the accuracy of results because it would not operate reliably.

Yet many police department spokesmen vouched for the accuracy of the machines.

Most states allow officers to punish drivers who refuse a Breathalyzer on the spot and refusal to submit to the test could be used against the driver in a subsequent trial. Even if they later submit to a blood test, they can be detained for refusing to cooperate with the field sobriety test in the first place. This issue cuts both ways; not only could thousands of citizens have been falsely charged with various degrees of DUI offenses, but a potentially equal number of legitimate cases could be tossed out if breathalyzer results are determined to be insufficient grounds for a DUI arrest.

According to the report, more than 30,000 cases have been thrown out just in the past 12 months, with judges citing everything from human error to lax government oversight.