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Fighting Drunk Driving Charges by Challenging Breath Test Results
Courts have ruled that breath-test device manufactures are required to provide source codes to accused drunk drivers that have reason to challenge the results.

Having a drink or two at an after-work happy hour or at dinner with friends or family usually doesn’t bring a second thought . . . until a cop is seen on the side of the road. Then the usual thoughts and doubts are likely to arise: Did I drink too much? Am I swerving? I don’t think I’m drunk, but am I over the legal limit?

If by chance the officer pulls you over and arrests you on suspicion of DUI, three basic types of tests may be used to determine your blood alcohol concentration (BAC): a breath test, a blood test and a urine test. Of the three types, breath tests are most common, and currently, a source of controversy.

For people charged with driving under the influence (DUI), the typical chain of events is as follows: police stop a driver on suspicion of DUI; police will attempt to gather clues, visually and otherwise, that indicate the driver may be impaired; police will order the driver out of his or her vehicle to submit to standardized field sobriety tests; the driver is arrested for DUI; the police officer requests that the driver take a breath test; the breath test indicates that the driver has a BAC of 0.08 or higher; and then the driver either fights the charges in a trial or accepts a plea agreement. The controversy usually arises when the accused driver challenges the results of the breath test in a trial.

Breath Test Source Codes

To challenge the reliability of breath test results, DUI defense lawyers often request access to the “source codes” of the testing devices. If obtained, the source codes would provide the accused driver and his or her attorney with the formula of how the device calculates BAC, allowing the lawyer to challenge the validity of the test result. However, manufactures are obstinate in their refusal to provide source code information, even in the face of court orders requiring them to do so, claiming that the source codes are protected proprietary information.

In recent years, state courts, including the Supreme Court of Minnesota, have ruled that breath test manufacturers must provide source codes to a driver accused of DUI if there is “some reason” to challenge the validity of the results or the source code. Specifically, the Minnesota case involved the manufacturer of the Intoxilyzer 500EN breath test device.

While manufacturers insist that the results of their breath test devices are reliable, anecdotal evidence indicates otherwise, and admitting that their products give inaccurate results is bad for business. A Cleveland.com article reported that Alfred E. Staubus, a breath machine expert and professor emeritus at Ohio State University, claimed that the Intoxilyzer 8000 provided a wide range of results when tested.

In fact, Professor Staubus said that, while conducting two tests on each device after drinking alcohol, he was able to obtain four different readings, two of which put his BAC above Ohio’s legal limit of 0.08.

For people accused of drunk driving, the suspected unreliability of breath test devices may provide a way to challenge the charges they face. If you have been accused of drunk driving in Ohio, speak with an experienced DUI defense attorney to discuss ways to defend your case.

Keywords: breath test
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