Draeger AlcoTest Breath Machine’s Accuracy Called Into Question
Posted Wednesday, November 13, 2019 by Andrew Charles Huff
Many of the alcohol breath test machines used by police on DUI cases can often be unreliable, according to a recent New York Times investigation. The investigation found these machines showing skewed results with alarming frequency, even though they are marketed as precise to the third decimal place.
For example, various judges in Massachusetts and New Jersey have thrown out more than 30,000 breath tests in the past 12 months alone, largely because of human errors and lax governmental oversight. Across the country, thousands of other tests also have been invalidated in recent years.
The machines are sensitive scientific instruments, and in many cases they haven’t been properly calibrated, yielding results that were at times 40 percent too high. Maintaining these machines is up to police departments that sometimes have shoddy standards and lack expertise. Technical experts have found serious programming mistakes in the machines’ software. Various states have picked devices that their own experts didn’t trust and have disabled safeguards meant to ensure the tests’ accuracy.
A county judge in Pennsylvania called it “extremely questionable” whether any of his state’s breath tests could withstand serious scrutiny. In response, local prosecutors stopped using them. In Florida, a panel of judges described their state’s instrument as a “magic black box” with “significant and continued anomalies.” Even some industry veterans say the machines should not be de facto arbiters of guilt. “The tests were never meant to be used that way,” said John Fusco, who ran National Patent Analytical Systems, a maker of breath-testing devices.Yet the tests have become all but unavoidable. Every state punishes drivers who refuse to take one when ordered by a police officer.
The Dräger Alcotest 9510 in Washington
Washington state uses the Dräger Alcotest 9510 machine and here’s how it works: When a person breathes into the device, a beam of infrared light is shot through the sample. Chemicals, including the ethanol in alcoholic drinks, absorb light to varying degrees. By analyzing how much light is absorbed, the instrument can identify the type of chemical and the amount of it present. This machine also use a fuel-cell sensor — the same type of tool that is in portable devices. Each system is supposed to operate independently; if both return similar results, it’s argued to be an extra assurance that the measurement is accurate.
We on the defense side have repeatedly tried to forensically examine the machines, especially their software because inspecting the code could reveal any built-in flaws or assumptions the devices use in their calculations. But even procuring a machine is a challenge because manufacturers won’t sell them to the public. When our state decided to spend more than $1 million to replace its aging machines in 2009, the state police chose the Alcotest 9510 despite a report by their own scientist that described the machines as “not yet ready for implementation.”
Before rolling out the machines, state officials debated whether to spend tens of thousands of dollars on an outside expert to evaluate the software. Dr. Fiona Couper, a state toxicologist, emailed her colleagues: “I think we throw caution to the wind and proceed without paying up front for an independent evaluation.” In 2015, a local judge granted a request from defense lawyers to review the software underpinning the state’s Alcotest machines. That task fell to a consulting company run by two veteran programmers and security experts, Robert Walker and Falcon Momot. Dräger insisted on extraordinary security. It demanded that its software be reviewed on an isolated computer network and that the state police be able to inspect the testers’ equipment, according to court documents. After a couple weeks dissecting the Alcotest code, they wrote a nine-page draft report, “Defective Design = Reasonable Doubt.” They planned to dig further, but things went awry when they shared their report with defense lawyers at a convention.
However, Dräger sent Mr. Walker a letter demanding that he and Mr. Momot ask anyone with a copy of their report to destroy it — including the lawyers who hired them — and to stay silent about the instruments’ inner workings. Facing a giant company, Mr. Walker felt he had no choice but to comply.
The report said the Alcotest 9510 was “not a sophisticated scientific measurement instrument” and “does not adhere to even basic standards of measurement.” It described a calculation error that Mr. Walker and Mr. Momot believed could round up some results. And it found that certain safeguards had been disabled.Among them: Washington’s machines weren’t measuring drivers’ breath temperatures. Breath samples that are above 93.2 degrees — as most are — can trigger inaccurately high results.
Washington had decided against spending more on a sensor that would check breath temperature and allow the software to adjust for it, according to Mr. Shaffer. He said Washington wasn’t alone; most of Dräger’s American clients skip the sensors.The Washington State Patrol has insisted they are confident in the machine’s accuracy and reliability and do not believe that the breath temperature sensor was needed to produce accurate results.
See https://www.nytimes.com › business › drunk-driving-breath
