From today’s New York Times: 
A Lawyer in Minnesota Challenges the Accuracy of D.W.I. Breath Tests By TIMOTHY WILLIAMS Published: August 19, 2011 For nearly five years, the accuracy of drunken driven tests administered with a breath testing device used by Minnesota law enforcement agencies has been in question. About 4,000 people in 69 Minnesota counties have challenged the results based on what they believe to be the device’s faulty readings of blood-alcohol levels. The state has maintained that the breath test results are accurate and that those found to have been driving with alcohol levels above the legal limit should be punished. This year, a judge ruled that although the device’s source code contained errors, its shortcomings did not affect the accuracy of the results. The decision was appealed, and the case is before the Minnesota Supreme Court. Ryan Pacyga, a lawyer who represents nearly 200 of the people accused of drunken driving, and who are now challenging the results, discusses. Q Please describe what is at issue with this device. A The machine is called the Intoxilyzer 5000EN. It is manufactured by a Kentucky company that sold the machines to Minnesota law enforcement. It uses infrared technology to measure particulate matter, and then uses a mathematical formula to convert it to what the blood-alcohol level would be. That’s because our law in Minnesota says it’s illegal to have a blood-alcohol content of .08 or more, so any test other than blood — like breath and urine — has to use a conversion rate to convert the reading into its blood-alcohol equivalent. The machine is somewhat antiquated — akin somewhat to an old Atari machine game console. There is a lawyer in the state who got the idea we should ask for the source codes for these machines, which are software updates that from time to time the manufacturer sends out. At times, Minnesota has installed the source codes. At times, it has not. That’s problem No. 1. Problem No. 2 is we want to test the source codes themselves because it is the source code that is the accuser, not the officer. Some judges started granting our requests to test the source code. Some said it was irrelevant. Prosecutors said, “We don’t have access to the source codes.” And then the manufacturers said they weren’t going to release the source code because it was akin to Coca-Cola’s secret formula. Q How long do you believe there has been a problem with the Intoxilyzer, and what made people start looking into it? A The suspicion is that this probably started a long time ago. The more air you blow into the machine, the higher the alcohol rate it registers. You have officers saying, “Blow harder. Blow harder,” as people are blowing into these machines. I’ve seen it happen time and again. In some cases, if you didn’t blow enough air into a machine you get what is called a “deficient sample,” which is qualified as a refusal. A refusal takes a harsher punishment in Minnesota.” [Note: The state and the manufacturer dispute that blowing harder is linked to higher readings.] I’ve handled over 1,000 D.W.I.’s in the last seven years and always look at the breath volume and compare the two samples [tests consist of two breaths into the Intoxilyzer]. I’ve seen this. I don’t know whether it could be tested or if it’s been tested. It’s kind of anecdotal. The other thing is this machine uses a control — a simulated solution control that is usually between a .078 and .082 when it is put into the machine. When the machine does the “control” and “replicate,” I often see that, despite knowing the control is a given value, the machine measures it higher, or lower. The point is that it knows what the control is, and it still isn’t measuring it right. The state says it’s within an acceptable limit. It may be acceptable to the state, but if you are a defendant, it’s not so cool. Q How many cases are involved here? A Over all, tens of thousands of tests probably over five or six years. A lot of lawyers never challenged the tests. We’re probably down to around 4,000 now. I’ve got over 160 people myself. My understanding is that is the second largest group in the state. Q Why is this issue important? A In some form or other, everyone involved in this is fighting for their lives. Someone who drives as part of a job — a truck driver, someone who makes deliveries, a traveling salesman — they’re going to lose that job. They’ve had training for their jobs and that’s all the training they have, and especially in this economy, their prospects for employment are not good. There are mechanics, they have to test-drive cars. They’re out of work. There are also background checks for white-collar workers. There’s not a lot of tolerance for a D.W.I. A lot of people are getting screened out because employers think if you have a D.W.I., you must be an alcoholic.
