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Portable breath tests are unreliable in DUI cases

On Behalf of | Jan 13, 2020 | DUI/DWI Defense |

More than 1 million Americans are arrested for drunk driving each year after going through a litany of tests, including portable breath tests, which are designed to measure a person’s blood alcohol concentration (BAC).

However, a New York Times investigation reveals many of the devices used in measuring BAC are unreliable, resulting in flawed measurements and forcing many judges to disallow the readings to be used as evidence.

Thousands of breath test results thrown out

Breath test devices are a bedrock in proving DUI charges and are found in just about every police station across the United States. While marketed as being accurate within three decimal points, many routinely yield results that are off by as much as 40%.

As a result, judges in Massachusetts and New Jersey threw out more than 30,000 tests over the past year due to human error and careless oversight. Judges in Queens County, New York, have also tossed out individual cases over questions about the machines’ accuracy.

Reasons for flawed test results

Breathalyzers and other portable breath tests are sensitive scientific instruments that require stringent standards for setup and maintenance. Errors can frequently happen when:

  • Devices are not properly calibrated before being put into use
  • Officers are not adequately trained to administer the tests
  • Software errors and programming mistakes occur
  • False positives are registered in people ingesting certain types of medication, foods and other substances

Thousands of cases are in limbo

Tens of thousands of breath test results have been discarded in pending DUI cases across the country, while in New Jersey and Massachusetts, another 42,000 convictions are at risk over flawed data. Thousands of others have been acquitted in cases without other credible evidence.

Many drivers fear they have no recourse if their BAC is 0.08% or higher when taking a breath test after being pulled over. If you are charged with DUI, an experienced defense attorney will challenge those results and fight for your rights in court.