DUI Cases To Be Tossed After Faulty Breathalyzers Exposed

Intoxilyzer (Comstock/Thinkstock)

A drunk driving trial in Pennsylvania has called into question the reliability of a popular breathalyzer device used to measure drivers’ blood alcohol content and could have far-reaching consequences for DUI cases across the nation.

Dauphin County Court of Common Pleas Judge Lawrence F. Clark Jr. issued a ruling this week that breathalyzer readings in the state could only be used as evidence if they were between .05 and .15 because police only calibrate them between those levels.

“The unvarnished facts of this case ultimately establish that the array of breath testing devices presently utilized in this commonwealth,” Clark’s decision said, “are not capable of providing a legally acceptable blood alcohol content reading, which is derived from a defendant’s breath, outside of the limited linear dynamic range of 0.05 percent to 0.15 percent.” The legal limit for driving is .08 percent.

Beyond the local calibration issue, testimony from an employee of CMI, Inc, the manufacturer of the widely-used breathalyzer device Intoxilyzer 5000, brought to light internal testing conditions that violate Pennsylvania law and make the use of the devices as evidence questionable nationwide.

Questionable Science

Steven B. Epstein

During the trial, Brian T. Faulkner, an engineer at CMI, acknowledged that the manufacturer initially calibrated the simulated solution, a concentration of ethyl alcohol used by the device for a baseline when testing a DUI suspect’s breath, in house. Right off the bat, Pennsylvania law stipulates that testing of the solution must be done in an independent laboratory, which means the state probably shouldn’t be using the devices at all.

But even in states that don’t have similar laws, DUI defense attorneys could use the lack of independent verification to challenge the trustworthiness of the manufacturer. “More important than principle of precedent and a Pennsylvania trial court decision’s impact is the testimony itself of Mr. Faulkner which calls into question the reliability of CMI,” says Steven B. Epstein, founding partner at New York firm Barket, Marion and principal instructor for The Legal Aid Society of the City of New York in the area of DWI. “It’s kind of like that scene in the Wizard of Oz when Toto pulls open the curtain.”

In addition to bypassing outside verification, Faulker’s testimony brought up an unusual way in which CMI used a zero reading when making initial calibrations that could potentially skew the results when matching device readings to different levels of blood alcohol content.

“The scientific literature is clear,” Epstein says. “They are essentially forcing data through the zero point on their data chart, making it forensically unreliable.”

Nationwide Implications

Again, the apparent flaws in the CMI testing process are something that attorneys in other jurisdictions could bring up in their defense cases. “What I understand is that the laws of science cross geographical boundaries,” says Epstein. “This is applicable in other courtrooms in the United States.”

Other defense attorneys could also check at what levels breathalyzer devices are calibrated by their local law enforcement agencies and attempt to build a defense around that — note that the Pennsylvania judge could have tossed breathalyzer results outside the local calibration range of .05 to .15 without even taking into account all the reliability problems of the manufacturer.

The practical application for the moment, while waiting for a potential appeal to a higher court, is that state police in Pennsylvania are immediately switching to blood tests in lieu of breathalyzer tests for DUI suspects. The long term effect of the issues raised at the trail could mean a larger shift nationwide away from breathalyzers, which already faced criticism for giving unreliable readings based on outdated technology.

“It throws into question if it’s even okay for them to do breath testing at all,” Epstein says. “It could bring more blood testing, using technology other than 1950s technology. Using modern science, which is what we should be doing.”