September 17, 2013 by Lawrence Koplow
Filed under Aggavated DUI, Alcohol, Arizona DUI Laws, Blood, Breath Testing, DUI, DUI Defenses, DUI Trials, Felony, Forensic, Phoenix, Science, Scottsdale, Super Extreme DUI, Testing.
In DUI cases, a machine called a gas chromatograph is often used to measure an alcohol concentration in a blood sample. The measurement, which the machine prints at the end of the process, is called a reported result. We are finally at the point in Arizona, where courts are starting to recognize that merely providing a reported result is not sufficient evidence. The law is coming to the same realization that science did many years ago: a reported result from a machine is an incomplete measurement.
A complete measurement includes more than just a reported result. As a matter of fact, simply providing a reported result is often misleading. A reported result is only complete when accompanied by a “statement of its uncertainty.” See NIST Technical Note 1297, 1994 Edition. No measurement is perfect. The result of any measurement is only an estimation of its value. A “statement of uncertainty” is the range of doubt that exists regarding a measurement.
A complete test result, must also include:
- a “Range of Uncertainty” and;
- a “Confidence Interval.”
To illustrate, let’s assume that a blood test result was .100. Let’s also assume, based on a review of the machine’s prior performance, a “range of uncertainty” was determined to be ± 5%, with a “confidence interval” of 100%. This means, the reported result could be as low as a .095 and as high as a .105. Moreover, this also means, if the same blood sample were repeatedly tested on this equipment, the result would only be outside of the ± 5% range 1 out of a million times. If this statistic were true, this would certainty be a reported result that you could trust.
On the other hand, what if for the same reported result of .100 the range was ± 30%, with a confidence interval of 50%? Here, this means the reported result could be as low as .070 or as high as .130. Furthermore, if you continued to test this sample on the same equipment, 300,000 times of out of a million, the reported result would be outside the range stated above.
When comparing the two complete test results, you can see that providing a mere reported result does not tell us the whole story. Merely telling us the reported result can actually tell us a very misleading story. Science will not accept incomplete measurements. Why should the law?
In July of 2012, I asked a member of the Scottsdale Crime Lab for an interview about some rumors. She refused and told me to get a court order. At that time I was surprised. Why would she refuse to do a routine interview? Today we know the answer.
Today we now know that: (1) the Scottsdale Crime Lab’s blood testing equipment is unreliable; and (2) the testimony of the crime lab personnel is not trustworthy. Don’t take my word for it – just read the court’s opinion by clicking here.
The truth of the matter is we don’t really know. Most labs in the Phoenix Arizona area claim to be accurate within 5%. That means if your blood result came back at .08, then the true result can be anywhere from 5% lower or 5% higher.
Other scientific organizations claim 5% is not a realistic range of accuracy. For example, the American Academy of Forensic Sciences claims that the accepted range of accuracy is 10% higher or lower.
After interviewing toxicologists over 100 times, doing a substantial number of DUI trials with blood results at issue, I am convinced that the accuracy is totally dependent on the procedures used by the lab, and most labs overstate their accuracy.
To support my conclusion, I need to explain how blood testing with a gas chromatograph works. At its most basic level, gas chromatography simply compares known alcohol concentrations to unknown blood samples. A blood tester does not inherently know what a blood alcohol concentration (BAC) is. You must calibrate it every time you do a test. You teach the machine what a .08 is by putting known alcohol concentrations into it, and essentially build a ruler.
Most labs in the Phoenix area put four known alcohol concentrations into the blood tester to build their ruler. These known concentrations are called calibrators. It is important to remember these calibrators are water based. That is, they are known alcohol concentrations in water. See the graphic below for an illustration.
As you can see in the example, there are four points on the ruler. The blood tester simply connects the dots on the ruler. If the four places on the ruler are accurate, then you should have a fairly accurate ruler. However, many labs make their own calibrators, and there is no way to know how accurate the ruler really is. There is no outside agency auditing their work. All we have is their word that they are accurate.
In addition, while it is a good first step to be able to build a ruler using water and alcohol, we are not testing alcohol in water in DUI cases. We are testing alcohol in blood. In science, we need to take into account what is known as the matrix effect. Simply put, water and blood are not the same substance. Water does not have red blood cells, white blood cells, plasma, virus, and bacteria. In order to measure alcohol in blood, we need a blood-based ruler. However, law enforcement labs do not actually use a blood-based ruler. This is where the procedures of the lab really make a difference.
Labs will use a known concentration of alcohol in blood and compare it to their water-based ruler. This is known as a calibrator. This procedure may be acceptable if done enough times with an accurate blood based sample.
Here is the problem. There are very few companies that make the blood based alcohol concentrations, they are not accurate, and some labs use only one calibrator (not four like the water-based.) When the blood-based alcohol sample comes from the manufacturer, there is an insert. The insert tells you that the stated blood alcohol concentration is just a target value. It states that the known concentration it is really just a range. For example, I recently had a case with a blood-based control with a target value of .182. However, upon reviewing the insert that came with the sample, according to the manufacturer, .182 could be anywhere between a .166 and a .198. Thus, the ruler used is not as accurate as we would like it to be. That is a tremendous range when we are trying to determine someone’s true blood alcohol concentration. The picture below illustrates what the blood-based ruler looks like with only one this one known value.
As you can see, you can’t build a ruler with only one point on a line. Thus, with using only one known value, your ruler just is not very accurate – unlike the water-based ruler. The less accurate your ruler is, the less accurate your test result will be. Consequently, the true range of accuracy could be significantly greater than even 10%.
Some things in life seem obvious. It is hotter in the summer. It is colder in the winter. The government must get a warrant to stick a needle in your arm before they forcibly take your blood. However, this last presumption has not been so obvious in Arizona.
For years in Arizona, attorneys have been arguing that law enforcement must get a warrant before taking your blood during a DUI investigation. Unless, of course, the person “expressly consents” to the blood draw. However, many Arizona courts have held that, under Arizona law, we should "imply" your consent to the blood test. Thus, there is no need to ask for your consent, nor to get a warrant before taking blood.
In most DUI cases, officers ask the person suspected of DUI if they will consent to the blood draw. The officer will explain that if you refuse to give consent, a one (1) year license revocation will be triggered. Moreover, the officer will likely inform you that they will also get a telephonic warrant, in a matter of minutes, and forcibly take your blood. Consequently, the majority of people do give consent to the blood draw. This scenario is perfectly legal.
However, every year I see a number cases where law enforcement just takes the person’s blood without asking for consent. They merely say "give me your arm" and take the blood. Most experienced DUI officers will not engage in such conduct. Yet this situation keeps occurring. And until now, many courts have upheld the officer's actions.
On September 1, 2009, the Arizona Court of Appeals stated the obvious. They held that law enforcement must obtain a search warrant to take a DUI suspects blood - unless the person “expressly agrees” to have their blood drawn. The Court reasoned:
Arizona’s Implied Consent Law, A.R.S. § 28-1321, requires the State to obtain a warrant before drawing a blood sample from a DUI suspect unless the suspect “expressly agree[s]” to submit to the blood test. A.R.S. § 28-1321(B), (D) (Supp. 2005).
We hold that the “express agreement” required by the statute must be affirmatively and unequivocally manifested by words or conduct, and may not be inferred from a suspect’s mere failure to communicate clear objection to the test.
In sum, there is nothing “obvious” about Arizona DUI laws.
Arizona is one of a few states that has created something referred to as "Super Extreme DUI." A DUI is "Super Extreme" if a person's blood alcohol concentration is .200 or above. While this crime is still a misdemeanor, it carries a minimum jail term that is greater than most first time felonies. There are several characteristics of this crime that make it unique. Here are the five most important:
1. An extended period of an Ignition Interlock Device. All Arizona DUI convictions require a person to install and maintain an ignition interlock device. For a first time regular DUI, the minimum period is one year. A conviction of Super Extreme DUI requires a minimum period of 18 months (or one and one-half years.)
2. Extended jail period. For a regular DUI conviction, there is a minimum jail term of 1 day. For an extreme DUI (BAC result of .150 and below a .200) conviction, there is a minimum jail term of 30 days. For an Arizona Super Extreme DUI, the minimum jail term is 45 days.
3. A better chance of getting your name in lights. The Maricopa County Attorneys' Office has a website that posts booking photos of DUI offenders. While they do not provide explicit details of how they choose who they post pictures of, we do know that they focus on people alleged to have higher blood alcohol test results (i.e. "Super Extreme DUI" and "Extreme DUI.")
4. Out of state offenders will probably go to trial. If you live in another state and get a "Super Extreme DUI", you will have an inherent difficulty with taking a plea offer. Many prosecuting offices offer long periods of jail for these cases. It is not uncommon for them to offer the same amount of jail the person may get if they went to trial and lost. For the person that lives in Arizona, they may be be able to maintain their employment during their jail term if granted work release and / or home detention. However, out of state offenders may not have these options. While most Arizona courts will permit them to do their jail out of state, there are very few out of state jails that will accommodate them. Finding a jail in someone's home state for a few days can usually be accomplished. When it comes to jail terms of 30 to 45 days, it is nearly impossible. Most out of state jails will not accommodate these requests. Consequently, an out of state offender may need to go to trial and fight the Super Extreme allegation. If successful, on that count alone, the minimum jail can be significantly reduced. Thus, trial is often times the best option in these cases.
5. Simply being charged with "Super Extreme DUI" does not mean you will be convicted of "Super Extreme DUI." While prosecutors tend to offer extended periods of jail on these cases, that does not mean a reduction (or even dismissal) is not possible. There are several factors that need to be examined: (1) How far above a .200 is the test result? (2) Were there any problems with the blood testing process? (3) How bad was the driving prior to the traffic stop? (4) Is there a disconnect between how the person was acting and the test result? and (5) Are there any procedural or constitutional violations? Moreover, there are many other factors that may affect the outcome of the case. The general concept is that if the government believes they might lose the case, the better the chance of a reduced plea offer.
In sum, Arizona Super Extreme DUI convictions are truly unique, in that the increased penalties for this misdemeanor can be more onerous than many felonies.
I ran across an excellent post discussing the source code issue. That is, the fight between criminal defense attorneys and the maker of the breath tester (CMI) to disclose the code used in their breath testers. CMI will not allow an inspection of the code. Consequently, it cannot be checked for accuracy. CMI essentially tells everyone charged with DUI to "just trust us."
Ed Brayton, a journalist and the co-founder of Michigan Citizens for Science, discusses the source code litigation in Florida.
Here's a very interesting case from Florida, where an appeals court has upheld a lower court ruling that threw out evidence from a breathalyzer test in a drunk driving case because the manufacturer of the device refused to release the source code and allow defense experts to analyze the accuracy of the machines.
The results of breath tests in more than 100 local drunken-driving cases will not be allowed at trial, a judge announced Tuesday.
The validity of those breathalyzer tests has been challenged for more than three years because of the Intoxilyzer 5000, a machine that uses a breath sample to measure a person's blood-alcohol content.
Manatee County Judge Doug Henderson ruled two years ago that any Intoxilyzer 5000 tests were inadmissible in trial, but prosecutors appealed. On Tuesday, Henderson told lawyers that his ruling had been affirmed by the Second District Court of Appeal and Circuit Court.
Breath analysis machines are notoriously inaccurate and this has been a problem for a very long time. Dr. David Hanson, a sociologist who has written on this issue for decades, writes:
Breath analyzers (Breathalyzer, Intoxilyzer, Alcosensor, Alcoscan and BAC Datamaster are common brand names) don't actually test blood alcohol concentration (BAC), which requires the analysis of a blood sample. Instead, they estimate BAC indirectly. Different types of machine use different techniqes and larger machines generally yield better estimates than do hand-held models. Therefore, some states don't permit data or "readings" from hand-held machines to be presented as evidence in court. South Dakota does not even permit evidence from any type or size breath tester but relies entirely on blood tests to ensure accuracy and protect the innocent.
A major problem with some machines is that they not only identify the ethyl alcohol (or ethanol) found in alcohol beverages, but also other substances similar in molecular structure. Those machines identify any compound containing the methyl group structure. Over one hundred compounds can be found in the human breath at any one time and 70 to 80 percent of them contain methyl group structure and will be incorrectly detected as ethyl alcohol. Important is the fact that the more different ethyl group substances the machine detects, the higher will be the false BAC estimate.
The National Highway Traffic Safety Administration (NHTSA) has found that dieters and diabetics can have acetone levels hundreds and even thousand of times higher than that in others. Acetone is one of the many substances that can be falsely identified as ethyl alcohol by some breath machines.
One investigator has reported that alcohol-free subjects can generate BAC readings of about .05 after eating various types of bread products.
Substances in the environment can also lead to false BAC readings. For example, an alcohol-free subject was asked to apply a pint of contact cement to a piece of plywood and then to apply a gallon of oil-base paint to a wall. The total activity lasted about an hour. Twenty minutes later the subject was tested on an Intoxilyzer, which registered a BAC of .12 percent. This level is 50% higher than a BAC of .08, which constitutes legal intoxication in many states.
Similarly, a painter with a protective mask spray painted a room for 20 minutes. Although a blood test showed no alcohol, an Intoxilyzer falsely reported his BAC as .075.
Any number of other products found in the environment can cause erroneous BAC results. These include compounds found in lacquers, paint removers, celluloid, gasoline, and cleaning fluids.
Other common things that can cause false BAC levels are alcohol, blood or vomit in the subject's mouth, electrical interference from cell phones and police radios, tobacco smoke, dirt, and moisture.
Breath testers can be very sensitive to temperature and will give false reasings if not adjusted or recalibrated to account for ambient or surrounding air temperatures. The temperature of the subject is also very important. Each one degree of body temperature above normal will cause a substantial elevation (about 8%) in apparent BAC.
Many breath testing machines asume a 2,100-to-1 ratio in converting alcohol in the breath to estimates of alcohol in the blood. However, this ratio varies from 1,900 to 2,400 among people and also within a person over time. This variation will lead to false BAC readings.
Physical activity and hyperventilation can lower apparent BAC levels. One study found that the BAC readings of subjects decreased 11 to 14% after running up one flight of stairs and 22-25% after doing so twice. Another study found a 15% decrease in BAC readings after vigorous exercise or hyperventilaion.
Some breath analysis machinnes assume a hematocrit (cell volume of blood) of 47%. However, hematocrit values range from 42 to 52% in men and from 37 to 47% in women. A person with a lower hematocrit will have a falsely high BAC reading.
It's about time a judge took a stand on this issue.