Category Archives: Field Evidence

Supreme Court OKs Forced Blood — After 3 Breath Tests

On January 18, 2005, the U.S. Supreme Court declined to review a state supreme court case endorsing the nonconsensual extraction of a blood sample from a DUI suspect — after he had already consented to three earlier breath tests. On February 19, 2002, police in Wisconsin pulled over Jacob Faust as he left a bar. Faust admitted that he had five brandies and failed the field sobriety tests. He voluntarily submitted to a roadside breath test; the results indicated a blood-alcohol concentration of .13% — well above Wisconsin’s .08% legal limit. He was arrested and, at the police station, agreed to take another breath test. Two separate tests on the breathalyzer indicated BACs of .09%. The officer then asked Faust to submit to the withdrawal of a blood sample.

Having already taken three breath tests, Faust finally refused further testing. He was immediately served with a notice of license suspension for refusing and taken to a hospital where a blood sample was drawn. The result of the blood test was .10%, almost the same as at the station. At a suppression hearing, the officer admitted it was not departmental policy to demand further tests and he did not suspect the use of drugs: he simply wanted "additional evidence" because Faust was only .01% over the limit. The trial court granted the motion to suppress, and the Court of Appeals affiirmed:

"Once an individual arrested on probable cause for OWI has provided a satisfactory and useable chemical test, the exigent circumstances justifying a warrantless and nonconsensual blood draw no longer exists."

In a 4-3 decision, the Wisconsin Supreme Court reversed, holding that "(t)he nature of the evidence sought — that is, the rapid dissipation of alcohol from the bloodstream — not the existence of other evidence, determines the exigency." (Of course, by this reasoning the police can take as many chemical tests — 15 or 20 — as they want; there is almost no limit since alcohol will continue to dissipate for hours.) Amazingly, the Court further found that the police had a right to additional tests since they can’t predict whether a breath test will be found reliable in court. (In a footnote (fn28), the Wisconsin Supreme Court may have noted the real reason for this blatantly dishonest opinion: "There were 292 people killed and 6,570 injured as a result of alcohol-related motor vehicle crashes in Wisconsin during the year 2002…" In other words, the ends justify the means — the Constitution notwithstanding.) One of the three dissenting justices observed:

Without consent, without a warrant, and without exigent circumstances, the forced blood test in the present case violated the United States Constitution… The majority’s argument is essentially that because law enforcement officers do not know what will happen at trial (and no one does, of course), it was reasonable for them to take as many valid tests of the suspect’s blood alcohol as they thought necessary to sustain a conviction."

The U.S. Supreme Court denied a writ of certiorari (refused to hear the case). Wisconsin v. Faust, #04-471. Police are now apparently constitutionally free to give blood-alcohol tests as many times as they wish.

DUI, Field Sobriety Tests and “Circadian Rhythm”

Most drunk driving arrests take place at night, often after midnight. One reason for this is that many police officers engage in "cherry picking" — that is, the illegal practice of staking out bars and restaurants from about 10:00am to "closing time", pulling cars over on some pretext as patrons leave and drive away. It is during this period of time that the individual’s circadian rhythm is taking effect. The circadian rhythm is that 24-hour biological alarm clock in each of our bodies, most noticeable when we experience "jet lag".

Researchers have found that individuals will perform more poorly in tests during the low point of the circadian rhythm — that is, during the hours after midnight and into the early morning. It is just such tests — called "field sobriety tests" — that officers use to determine whether a driver is intoxicated or not. Specifically, British physicians and psychiatrists reported that "the same blood alcohol level is associated with a significantly greater impairment of different aspects of psychological funtioning when achieved in the morning." "Circadian Variation in Effects of Ethanol in Man", 18 (Supp. 1) Pharmacology, Biochemistry and Behavior 555. The researchers concluded that "the differences we have found…must be attributable to circadian change and susceptibility of the body to its effect."

Asthma Inhalers Cause High Breathalyzer Results

If you use asthma inhalers and are ever arrested for DUI, you should perhaps think twice about taking a breath test. Most inhalers operate primarily by injecting a mist containing a substantial quantity of alcohol into the lungs. As an example, one of the most commonly used inhalers, Primatene Mist, contains 34 percent alcohol. This alcohol does not pass into the blood stream, but remains in the alveolar lining of the lungs — from where it will be exhaled into the breath machine.

The problem is that "breathalyzers" are designed to assume that the breath sample contains alcohol which has been swallowed and then metabolized by the body before being diffused into the lungs. As I mentioned in an earlier post ("Breathalyzers — and Why They Don’t Work"), they are further designed to assume that there are 2100 units of alcohol in the blood for every unit measured on the breath. So the breathalyzer’s computer mistakenly multiplies the alcohol measured from the asthma inhaler 2100 times. In other words, a very tiny amount of alcohol in the lungs from the inhaler mist can have a very large effect on the machine’s reading.

Just to make things worse, scientists have found that some asthma inhalers can cause high readings on breath machines due, apparently, to the propellent gasses used in the aerosols, in particular, chlorofluorocarbons. See "Using Asthma Inhalers Can Give False Positive Results in Breath Tests", 324 British Medical Journal 756 (March, 2002). As I mentioned in another earlier post ("Why Breathalyzers Don’t Measure Alcohol"), one of the many design defects in breath machines is that they are non-specific — that is, they will falsely report thousands of different chemical compounds as being alcohol.

Why Breathalyzers Don’t Measure Alcohol

That’s right: Breathalyzers don’t actually measure alcohol. What they actually detect and measure is any chemical compund that contains the methyl group in its molecular structure. There are thousands of such compounds — including quite a few which can be found on the human breath. And this machine that determines a person’s guilt or innocence will "see" all of those chemicals as alcohol — and report a falsely high "blood-alcohol" concentration (BAC).

Most breath machines used in DUI cases by law enforcement today employ a technology called "infrared spectroscopy". The DUI suspect breathes through a tube connected to the machine and a breath sample is captured in a small "sample chamber" inside the machine. Then beams of infrared energy are shot through the captured breath sample. If there are any compounds containing the methyl group, they will absorb some of this energy; the more of the chemical compound in the breath sample, the more energy is absorbed. The more energy that is absorbed, the less infrared energy that reaches sensors at the other end of the sample chamber. And the less energy that is detected by the sensors, the higher the "blood-alcohol" reading.

Problem: the machine is designed to simply assume that the chemical compound absorbing the energy is alcohol. If a person has any of these other compounds on his breath, called "interferents" by the engineers, he will get a falsely high BAC test result. And if there are two or three such compounds on his breath, the machine will read a cumulative result: it will add them up and falsely report the total as the blood-alcohol level.

So what kinds of compounds may be on a person’s breath that can cause false BAC readings in a DUI case? In one study of eight men, 69 different compounds containing the methyl group were discovered. "Trace Composition of Human Respiratory Gas", 30 Archives of Environmental Health 290. In another study invoviing 28 subjects, researchers found that teh "combined expired air comprises at least 102 various organic compounds of endogenous and exogenous origin". "Characterization of Human Expired Air", 15 Journal of Chromatographic Sciences 240. And Camnadian scientists have discovered over 200 such compounds. "The Diagnostic Potential of Breath Analysis", 21(1) Clinical Chemistry 5.

What are these compounds? Are there any on my breath?

Well, for starters, diabetics with low blood sugar can have high levels of acetone — which is "seen" as alcohol by Breathalyzers. And scientific studies have found that people on diets can have reduced blood-sugar levels, causing acetone hundreds of times higher than found in normal individuals. Frank and Flores, "The Likelihood of Acetone Interference in Breath Alcohol Measurements", 3 Alcohol, Drugs and Driving 1. And there are many other so-called "interferents". See, for example, "Excretion of Low-Molecular Weight Volatile Substances in Human Breath: Focus on Endogenous Ethanol", 9 Journal of Analytical Toxicology 246.

If you are a smoker, your Breathalyzer result is likely to be higher than expected. The compound acetaldehyde — reported by the Breathalyzer as "alcohol" — is produced in the human body as a by-product in metabolizing consumed alcohol, and eventually passes into the lungs and breath. Researchers have discovered that levels of acetaldehyde in the lungs can be 30 times higher in smokers than in non-smokers. Result: higher BAC readings on the machine.

And then there are the industrial compounds: paint, glue, gasoline, thinners, and other compounds contain the methyl group. No, you don’t have to drink the stuff: simply absorbing it through your skin or inhaling the fumes can result in significant levels of the chemical in your body for hours or even days, depending upon the "half-life" of the compound. So if you’ve painted a room or siphoned some gasoline in the last day or two, don’t breath into a Breathalyzer.

Some law enforcement officials say that this is not a problem, claiming that levels of the compound would have to be at toxic levels to raise a breath test result to .08% or higher. These officials are displaying their ignorance of the science involved — specifically, of the partition ratio. This is the ratio of the compound found in the breath to that found in the blood. With ethanol, the ratio is 2100-to-1, which means that, on average, there will be 2100 units of alcohol in the blood for every unit found in the breath.

These officials are using this ratio for all compounds, but every compound has its own ratio. Toluene (found in paint, glue, thinners, cleaning solvents. etc.), for example, has a partition ratio of only 7-to-1; a far greater amount of toluene in the blood will pass into the breath, and so a much smaller amount in the body will have a far greater impact on the breath machine.

Warning: Breathalyzer in Use

Have you ever noticed those "Warning: Microwave in Use" signs in restaurants? It’s for folks who have heart pacemakers: There is a risk that the electromagnetic interference (EMI) from the microwave will interfere with the electronic circuitry in the customer’s pacemaker and cause it to malfunction. This phenomenon, often called radio frequency interference (RFI), can be a recurring problem with any instrument containing electronic circuitry.

Now try to think of some place in your neighborhood that is chock full of electronic gizmos constantly transmitting RFI 24 hours a day. How about a police station? Powerful dispatch radio transmitters, radio transmitters in squad cars in the parking lot, walkie-talkies in every officer’s belt, cell phones, computer cathode ray tubes, microwave relays, electronic door locks, microwave ovens, fluorescent lighting — a veritable jungle of RFI. Now let’s put a Breathalyzer smack in the middle of this police station. An instrument filled with sensitive electronic circuitry that has to analyze tiny amounts of alcohol in breath to an accuracy of one tenth of a percent…..

Just a theory of some DUI defense attorney? Consider a report from the National Bureau of Standards, under contract with the National Highway Traffic Safety Administration to conduct accuracy testing on breath machines (referred to in the report as "Evidential Breath Testing" devices, or "EBTs"):

The Washington D.C. Metropolitan Police Department reported to NHTSA that EBTs were found to display erroneous BAC [blood-alcohol content] readings in the presence of electromagnetic fields from radio transmission…. Representatives of NHTSA and NBS were given a demonstration by police officers who routinely conduct breath testing using an EBT in a mobile van. One police officer operated his handheld radio within 1 foot of the EBT and demonstrated that the electromagnetic field could severely affect the analysis of alcohol samples.

The National Bureau of Standards subsequently conducted the testing and subsequently reported that

These results show that EMI is a potential problem with many of the EBT units currently in use….The states may have to take interim measures to determine the extent of their individual problems with EMI affecting EBTs.

The reaction by the federal government to this report was, perhaps, predictable. Afraid that it would undermine public confidence in law enforcement methods, the government classified the document and then buried it. However, it was later resurrected by a Minneapolis DUI law firm’s Freedom of Information Act lawsuit. Most manufacturers of breath machines today quietly offer an "RFI detector" as an option in their products. Unfortunately, these "detectors" are unreliable and, in any event, are rarely purchased by law enforcement agencies.

Note: all 50 states now make it a crime to drive with a blood-alcohol level of .08% or higher. In most cases, the only evidence of this comes from the breath machine. The breath cannot be re-analyzed. The machine cannot be cross-examined.