???? People come in all shapes, sizes, ages, abilities and conditions. We’ll, not quite. People come in a range of shapes, sizes, ages and abilities. Of course, there is a national average, a national median and a national mean for all of these ranges. Sometimes it makes sense to speak about the national average. But when we make individual decisions about our own lives–such as, say, when we shop for clothes–we look to our own shape and size. We don’t buy clothes that would fit the average American; we buy clothes that fit our own bodies and our own tastes.
???? Unfortunately, in DWI cases, the police have been taught by the National Highway Transportation Safety Administration, to treat all of us as if we were average:
???? NHTSA recommends scoring a battery of field sobriety tests according to particular rules that are applied the same regardless of whether the subject is a healthy 19 year old in running shoes on a summer afternoon or an overweight 65 year old with a head cold and cowboy boots on an icy night. A misstep by the 65 year old will be treated the same as one by the 19 year old–it is a visual “clue” of impairment and only so many are necessary to “fail” the test. See, NHTSA DWI Standardized Field Sobriety Testing Student Manual (2007).
???? In an recent case, I represented a young woman who wore three and half inch heels when she performed the field sobriety tests on a cold night. Following NHTSA’s procedure, the officer gave her the option of performing the tests in her stocking feet on the cold and rough roadway. She declined and did the tests wearing her high heels. Even though neither NHTSA nor anybody else has ever attempted to standardize or validate these tests for women in high heels, the officer “scored” the test just as if she had a pair of tennis sneakers on. At trial, of course, he admitted that he probably couldn’t do the tests well in my client’s shoes.
???? Of course, you can always argue that the officer shouldn’t be allowed to testify to “clues” and individual “test failures” in the first place. But in many cases, regardless of whether this type of testimony is admissible, the officer will determine whether a driver is impaired based precisely on NHTSA’s reasoning that we are all average.
???? The same is unfortunately true for forensic breath testing. The goal of forensic breath testing is to determine, as accurately as possible, the percent of alcohol in the driver’s blood. Alcohol in the blood is what impairs our driving ability. Yet it is more convenient (for both the police and the driver) to take a breath alcohol test than a blood alcohol test–no needles are involved, no special medical training is necessary and the results are available immediately. But because the Intoxilyzer 5000 (the machine used in New Hampshire) and all similar devices express alcohol concentration as a single number rather than a rather large range of possible numbers–it assumes that we are all average. Here’s how:
???? 1. The law presumes that the ratio of:
Breath Alcohol (BrAC) / Blood Alcohol (BAC)
is the same for all of us. This presumption–equating BrAC with BAC–has been written into law in New Hampshire. See, RSA 259:3-b (defining Alcohol Concentration (AC) as either BrAc or BAC. Yet it is a lie. The ratio of BRAC to BAC (called the partition ratio) varies from person to person. And it varies within each individual person over time. It is true that that only a small percentage of the population has a significantly higher than average BrAC/BAC ratio. Indeed, the Intoxilyzer actually understates BAC for most drivers. But if you have a much higher than average BrAC/BAC ratio, the average fits you no better than a suit that’s three sizes too big. In your case, the Intoxilyzer 5000 result would overstate your actual blood alcohol concentration.
???? 2. BrAC depends on body temperature. The higher your temperature, the higher your Intoxilyzer results. While the range of human temperatures is pretty narrow–there’s nobody walking around at 107F and there’s nobody walking around at 93F–it is a range and if your temperature is significantly higher than average (like when you have a fever), your Intoxilyzer result will overstate your actual blood alcohol concentration.
???? 3. The Intoxilzyer assumes that none of us have gastric reflux. The “breath” that matters for breath alcohol testing is so-called “deep lung air.” Mouth air and stomach air should not be tested. Think of it–if you were sober but swirled a shot of Jack Daniels around in your mouth and spit it out, the breath from your mouth would have a very high alcohol concentration even though your deep lung air would have virtually none. Likewise, if you drank wine and then burped, alcohol filled stomach air would enter your mouth.
???? New Hampshire law requires the police to observe a driver for twenty minutes prior to an Intoxilyzer test so that (a) alcohol in the mouth will evaporate (although this does not always occur) and (b) the driver does not burp or otherwise let stomach air into his or her mouth. The twenty minute waiting period is a useful safeguard for most of us. But persons with gastric reflux continually have stomach air going into their mouths. When their mouths are connected to the Intoxilyzer, their stomach air goes into the machine. But the Intoxilyzer assumes we are all average and does nothing to take this fact into account.
The myth that we are all average is also applied when the State uses hospital blood tests (an issue which raises important privacy and privilege concerns). Hospitals test blood plasma, but alcohol concentration is defined as the percent of alcohol in whole blood. While the State toxicologists freely admit that Blood Plasma AC is greater than Whole Blood AC, they ignore the fact that the ratio between the two can vary dramatically from individual to individual (and within a given individual over time). Instead, they use the average ratio and testify that Blood Plasma AC is 15% to 20% higher than Whole Blood AC. While that may be true for most of us it may not be true for you. So your alcohol concentration might be much lower (0r higher) than the State toxicologist says.
???? Finally, State toxicologists assume we are all average when they attempt to extrapolate BrAC and BAC tests results to estimate alcohol concentration several hours earlier (a process called reverse extrapolation). This typically occurs when the BrAC reading is close to 0.8 but the test was taken a hour and half or more after the arrest. We metabolize alcohol at different rates. Yet the State toxicologists assumes that we all metabolize alcohol at the same rate. That’s great for many of us. But it may not be great for you.
