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Friday, August 19, 2011

"A Lawyer in Minnesota Challenges the Accuracy of D.W.I. Breath Tests"

From the New York Times. Here's an excerpt from the Q/A with the lawyer:

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. 

. . .

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.

http://lawprofessors.typepad.com/crimprof_blog/2011/08/a-lawyer-in-minnesota-challenges-the-accuracy-of-dwi-breath-tests.html

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Comments

The article could have at least made an attempt at truly examining the science of these time-tested instruments. Instead we have only the word of an attorney with a clearly vested interest attack their results. I'm sorry, I just don't think Mr. Pacyga's "anecdotal" accounts and Atari comparisons hold a candle to the studies which have verified the results time and again. Not to mention the fact that each time a sample is taken, the machine measures the alcohol content of a known reference sample (which is prepared using the alcohol content of a known solution, separate from infrared analysis). If the defendant's samples were inaccurate, the reference samples would show up as way off the mark, too.

Posted by: Jesse L. Davis | Aug 19, 2011 8:28:02 PM

HOG WASH TO JESSE L. DAVIS UNTIL YOU HAVE TRULY STUDIED THE SCIENCE OF BAC & HOW INEFFECTIVE & INADEQUATELY THE CURRENT BREATHE EQUIPMENT IN USE IS TO READING ACCURATE LEVELS OF BLOOD ALCOHOL, I SUGGEST YOU BITE YOUR TONGUE!

THERE ARE SO MANY DIFFERENT ELEMENTS AND FACTORS THAT CAN EFFECT BREATHE BAC SO THAT THE CURRENT INSTRUMENTS IN USE DO NOT, NOR CAN THEY, PROPERLY TEST ALL THOSE DIFFERING FACTORS/ELEMENTS. AN EXAMPLE IS AN ASTHMATIC PATIENT ON STEROIDAL INHALER; AN OVER WEIGHT DIABETIC HAVING A GLUCOSE CHANGE IN BLOOD SUGAR.

I SUGGEST YOU READ UP ON THE SCIENCE!!

Posted by: CJ | Aug 20, 2011 8:13:50 PM

Asthma and diabetes? This sounds like the closing argument in the lamest DWI trial ever. A)Much of the defense bar acts as if these breath tests happen in a vacuum, absent poor driving facts, admissions of drinking, etc. Most of the time, the breath results either confirm what the arresting officer already knows or show him that the subject holds their liquor even better than he expected. If a subject is having a diabetic event, it's going to become apparent long before the breath test enters the picture. And while a diabetic event might produce an odor of alcohol or acetone on the breath, it cannot and will not produce measurable amounts of ethyl alcohol in a breath test. B) The instrument tests for all manner of interferants, like exhaled medication. If something unexpected is detected, the instrument won't give a result at all, and prompts the officer to obtain a blood specimen. C) The defendant has to consent to a breath test. As a colleague of mine once said, you can't squeeze them like an accordion and make them blow a specimen.

Posted by: Jesse L. Davis | Sep 3, 2011 8:21:58 PM

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