FAQs

Are Breath Tests Accurate?

Keep in mind that a police-administered breath test creates an estimate of the amount of alcohol that is in your breath. Like all estimates, it can be accurate or inaccurate, depending upon the circumstance. However, breath alcohol levels do not necessarily accurately reflect blood alcohol levels. In other words, a sample of breath with a certain amount of alcohol in it may be accurately analyzed for the amount of alcohol in the specimen of breath, but it may bear little relationship to the amount of alcohol in the blood. This is because of several factors:

• The Intoxilyzer 8000, which is the machine used in Arizona, is acknowledged to have up to a 10% random error factor by the government.
• How hard and long you blow into the machine can results in an overestimation or underestimation of your actual blood alcohol content by as much as 15% in either direction.
• Your end-expired breath temperature and core-body temperature can make a difference of 8.6% for each degree centigrade that your temperature varies from what the machine expects. Studies show that the average human end-expired breath temperature is 35°C, but the machines are set to 34°C, which means that the average subject’s breath alcohol concentration is over-estimated by 8.6%.
• Hematocrit, which is the ratio of solids to liquids in your blood can have an effect of up to 14% in either direction.
• Partition Ratio is the ratio of alcohol in your blood to the alcohol in your breath. The machine is programmed to make a calculation, assuming that there are 2100 parts of alcohol in your blood for every one part in your breath. Unfortunately, humans vary from 900:1 all the way up to 3400:1, but the machine does not take that into account. This means that a person with a .034 breath alcohol content could have a police-administered test result that reads as high as .080 based on this factor, alone.

All of these factors are individual, which means that they can be additive, or cancel each other out. When added together, a police-reported breath test result could be as much as 105.6% too high or 109.6% too low.

How do the police test for alcohol in my blood?

Keep in mind that a police-administered blood test creates an estimate of the amount of alcohol that is in your blood. Like all estimates, it can be accurate or inaccurate, depending upon the circumstance. The police crime labs use head-space gas chromatography with a flame ionization detector to analyze blood samples. It is a very well-respected and reliable method of testing blood for alcohol, but the people who work in the crime labs often have minimal education, poor training, inadequate facilities and unscientific laboratory protocols.

Blood is collected in two grey-top tubes which should contain a preservative and anticoagulant (grey-top tubes are normally used in medicine for glucose-testing). One tube is for the crime lab to test and the other is preserved for the subject's independent testing purposes.

At the crime lab, one tube is opened and the contents are poured into a clean container. A measured amount of blood and a type of alcohol (usually n-propanol) are mixed together into a head-space vial, which is then crimp-sealed. The vial is placed into a rack called an auto-sampler with up to 123 other vials. Each vial is heated and rocked to allow volatile compounds to rise into the head-space above the liquid in the vial. When equilibrium of the ratio of volatile compounds in the liquid to the volatile compounds in the head-space is reached, the head-space gas is sampled.

A syringe pierces the crimp-seal and another gas (generally helium) is used to force the head-space gas out of the vial and into a hot injector port of a machine called a "gas chromatograph" (GC).

The head-space gas travels through a capillary column which is about 30 meters long and nearly as thin as a human hair. By chemical and mechanical means, the molecules traveling through the column are slowed down to different speeds, depending on the type of molecule. They elute (exit) the column at predictable times and are burned by a flame. The burning of the molecules creates ion energy which is measured by a flame ionization detector and converted by a computer formula to a blood alcohol estimate.

Head-space gas chromatography is a "separation science" and relies on the ability of the process to separate out various compounds and measure quantities so small that they cannot be seen with the human eye. Small mistakes in preparation of the sample will lead to large mistakes in the results.

What should I do if I receive a photo-ticket in Arizona?

You have four options upon receiving a photo-ticket in the mail. The first option is to accept responsibility and pay the ticket. Be aware that such tickets may carry points which add to your insurance-risk and costs.

The second option is to attend traffic school, if you are eligible (you may attend only once every two years). This avoids points being added to your license, but the school can be costly and time-consuming.

The third option is to respond to the photo-ticket that you received in the mail and fight it in court. Generally, the mailed ticket will have complete instructions on how to proceed with these first three options. What they won't tell you about, is your fourth option.

The fourth option is to ignore the ticket–that's right–ignore it. In Arizona, a civil traffic ticket is a complaint and an accompanying summons must be served on you. When the police write a ticket, the form is actually a "Complaint and Summons." Valid service of a complaint is accomplished by actually handing the ticket to you (police ask you to sign the ticket when you get one in-person to prove that you were aware of service). Service can also be accomplished by leaving the summons and complaint at your residence with a person who is at least 16 years old, and lives at the residence.

If that happens, do not ignore it. Once it is actually served, you must answer for it in some manner. If you do not answer for it, you may lose the case by default, your license could be suspended, and you may be responsible for collection fees. If you are served, you fight the ticket and lose, you will be responsible for paying for the cost of service of the summons in addition to the fine–generally service costs about $35-$50. The police have only 120 days from the date of the alleged violation within which to serve you.

How do machines test for alcohol in breath?

Although three types of breath-testing estimators are approved for use in Arizona, the police only use one–the Intoxilyzer 8000^© made by CMI, Incorporated, in Owensboro, Kentucky.

The Intoxilyzer 8000 uses Infrared Spectroscopy to analyze breath to create and estimated breath alcohol content. It does this by first projecting infrared (IR) light through a sample chamber at two IR detectors with only ambient air in the chamber. It measures the amount of IR light that strikes the detectors and sets up a baseline to compare to a subsequent breath sample.

Next, a person blows into the machine, filling the sample chamber with breath. The Intoxilyzer projects IR light through the breath sample at the detectors. The IR light excites the molecules in ethyl alcohol, causing the molecular bonds to bend, stretch and rock. This causes less IR light to strike the detectors. A difference in the amount of light which struck the detectors before and during breath samples is measured and a breath alcohol estimate is calculated by way of a secret formula known only to CMI.

The key to IR testing is that each organic molecule has a unique IR "fingerprint" which cannot be confused with any other molecule. While this may be true, neither the Intoxilyzer 8000 nor any other IR breath tester measure the entire molecule. Some IR breath testers measure up to five different IR wavelengths. The Intoxilyzer 8000 measures only two. By way of analogy, think of it as a roadmap. Your are told that I-10 passes through Tucson and crosses 18th Street and 22nd Street. Thus, any city through which I-10 crosses streets named 18th Street and 22nd Street is Tucson. At 2,460 miles in length, I-10 is the fourth longest Interstate Highway in the United States. Surely, somewhere along its route it passes through another city, crossing 18th Street and 22nd Street. Using Intoxilyzer IR technology, you would mistake that city for Tucson–and using Intoxilyzer IR technology, it can mistake other molecules for ethyl alcohol.

"Guilty" & "No Contest" What do they mean?

Sometimes it is necessary to accept a plea bargain in a criminal case and two types of plea may be offered: Guilty or No Contest. Whether your plea is Guilty or No Contest, the judge will enter a verdict of "Guilty" in your case. So, what is the difference?

"Guilty" means that you admit to all of the facts involved in the alleged crime. “No Contest” means that you do not admit to any facts, but you agree that if there were to be a trial, the government could prove its case against you, thus, you are not contesting the truthfulness or accuracy of their facts.

In most cases, there is not point in entering a No Contest plea. However, where there is civil liability involved as a result of the criminal act, a No Contest plea is valuable. Take, for example, a DUI accident case where the other party is injured. The victim claims that you were driving while under the influence, crashed, and that results in his injuries. If you plead guilty to the DUI charge and you are later sued by the victim, the victim would not have to prove that you were driving while under the influence in the civil lawsuit because you already admitted to it when you accepted the plea offer and pled guilty in the criminal case.

However, if you pled No Contest, since you had not admitted to the facts involved in the crime, the victim would have to prove that you were driving while under the influence in the civil lawsuit.

What are the permitted Blood Alcohol Levels in Arizona?

0.000 is the limit for minors (under 21 years of age).
0.040 is the limit for commercial drivers while driving a commercial vehicle.
0.080 is the lowest limit for all drivers, regardless of age or class of license.
0.150 is the Extreme DUI limit. Violation results in a higher penalty.
0.200 is the Super-Extreme DUI limit. Violation results in a higher penalty.

What is a "Standardized Field Sobriety Test"?

The National Highway Traffic Safety Administration ("NHTSA") has developed a battery of field sobriety tests, which are designed to detect the impaired driver. NHTSA believes that the tests the most effective procedures for testing drivers out in the field to determine whether or not they are intoxicated. The tests evaluate a concept known as divided attention. Divided attention requires an individual to concentrate on two or more things at once and driving is an example of a divided attention task. For example, a driver must simultaneously control steering, braking and acceleration, and react appropriately to changing conditions in order to operate a vehicle safely. Alcohol affects and reduces a person’s ability to divide their attention between tasks. Field sobriety tests that simulate the divided attention characteristics of driving are being used by police departments across the country.

There are four types of field sobriety tests. There are physical performance tests, mental performance tests, combined physical/mental performance tests (also called "divided attention" tests) and (4) eye impairment tests. There are only the three standardized and validated field sobriety tests (Walk-and-Turn, One-Leg-Stand, Horizontal Gaze Nystagmus).

"Standardized" means that the tests are given and evaluated in the prescribed manner, without deviation. "Validated" does not mean that the tests are "valid." "Validated" means that they have been shown to loosely correlate to a percentage chance that the subject is at or above a particular blood alcohol concentration.

Horizontal Gaze Nystagmu

Another field sobriety test is the horizontal gaze nystagmus ("HGN"). The HGN test assists police officers correctly distinguish suspects who are under the influence of alcohol from those who are not. The basis of this test rests the fact that alcohol affects the automatic tracking mechanisms of the eyes. Nystagmus is defined as an involuntary rapid movement of the eyeball, which may be horizontal, vertical, rotatory, or any combination. Alcohol slows down a person’s eyes' ability to rapidly track objects. This causes the eyes to jerk. Alcohol stimulates the nerve endings, making nystagmus more pronounced in someone who has been consuming alcohol. As a person's blood alcohol concentration rises, the eyes will "jerk" sooner than they would if a person had little or no alcohol as they move to the side. Remember, the HGN test claims to gauge the level of intoxication by measuring the involuntary jerking of the eyes.

The procedures used by police officers are set by the National Highway Traffic Safety Administration in the DWI Detection and Standardized Field Sobriety Testing Student Manual. Before the administration of the HGN test, the eyes are checked for equal tracking ability as well as equal pupil size. If an officer sees that the eyes are not track together or that the pupils are unequal in size, this should indicate that injuries or medical disorders are likely the cause of the nystagmus. The NHTSA standardized clues that the officers look for include lack of smooth pursuit, distinct nystagmus at maximum deviation and onset of nystagmus prior to reaching a 45 degree angle. The standardized administration procedures that officers should also use in the field include holding the stimulus 12-15 inches in front of the suspect's nose, keeping the tip of the stimulus slightly above the suspect's eyes, always moving the stimulus smoothly; always checking for all three clues in both eyes, starting with suspect's left eye, checking the clues in sequence: (1) lack of smooth pursuit, (2) distinct nystagmus at maximum deviation, (3) onset of nystagmus prior to 45 degrees; always checking for clues at least twice in each eye. The NHTSA manual identifies that there are no other "clues" are recognized by the NHTSA as valid indicators of HGN. Specifically, the NHTSA does not support the allegation that onset angle can reliably be used to estimate BAC, and considers any such estimation to be misuse of the horizontal gaze nystagmus test. The NHTSA propagates the standardized criteria for evaluating HGN. The maximum number of clues of horizontal gaze nystagmus suspect can exhibit is six, occurring if the suspect exhibited all three clues in each eye. If a suspect exhibits four or more clues, this should be considered evidence that the suspect's BAC is above .10

What Should I Do If Accused of a DUI?

There are many "DOs" and "DON'Ts" in a DUI situation. Below is a general guideline that I recommend anyone should follow if accused, whether drinking or not.

1. DO be courteous and polite to the police officer.
2. DO NOT argue with the officer.
3. DO NOT resist arrest.
4. DO NOT try to "explain" the situation to the officer.
5. DO ask to speak to an attorney IMMEDIATELY.
6. DO invoke your right to remain silent. Do not answer any questions. Do not volunteer any statements. Keep quiet.
7. DO NOT tell the officer what, when, or how much you have had to drink. If asked whether you have been drinking, simply decline to answer the question. Do not lie to the officer.
8. DO NOT take any Field Sobriety Tests. Do not let an officer "look into your eyes" or give you an "eye test." The "eye test", otherwise known as "Horizontal Gaze Nystagmus" (HGN) is the biggest scam perpetrated by law enforcement in the DUI arena. HGN is a very scientific test which is usually administered by a qualified physician to detect a head injury. In the hands of the police, it is nothing more than a tool to convict innocent people.
   Statistical analysis shows that only 1 in 10,000 officers will maintain better than a 90% accuracy rate on HGN tests, yet nearly every police officer I have ever met claims better than 90%. They all can't be 1 in 10,000. (Keep in mind that they keep their own statistics and there is no supervision).
   Perhaps Dr. L.F. Dell'Osso, Ph.D., a professor in the departments of Neurology and Biomedical Engineering at Case Western University and also Director of the Ocular Motor Laboratory at the VA Medical Center in Cleveland said it best when he wrote:
   

   More commonly, alcohol produces horizontal gaze-evoked nystagmus, and this has led to a "roadside sobriety" test conducted by law enforcement officers. Using nystagmus as an indicator of alcohol intoxication is an unfortunate choice. . .[I]t is unreasonable that such difficult judgments have been placed in the hands of minimally trained officers.
   Current Neuro-Ophthalmology 2:147-182, ©1989, Year Book Medical Publishers, Inc.

9. DO NOT take any balance tests--walk a straight line, stand on one leg, say or write the alphabet. You do not have to take such tests and you do not have to give a reason for refusing the tests. They can only be used against you. There is no "Pass/Fail" on these tests, only a "Fail" or the results are "Inconclusive."
   
   YOU CANNOT PASS A FIELD SOBRIETY TEST.
   The results are either "Failure" or "Inconclusive"
   There is no "Pass"
10. DO submit to a breath, blood, or urine test after the officer has read you an "Implied Consent/Admin Per Se" Affidavit. You will be asked to sign the affidavit and it will explain your rights about chemical testing.
11. DO Sign the citation form (it is not an admission of guilt--it is a promise to appear in court).
12. DO ask to be released for an independent blood test (this is at your own expense).

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