Blood, Breath, and Field Sobriety Testing
Arizona DUI law provides that the determination of your blood alcohol concentration (“BAC”) can be based on testing of the suspect's blood, breath, or urine, and that a person suspected of drunk driving has already given implied consent to the test. Of course, police officers retain the discretion to choose whether a blood, breath, or urine test will be administered.
The more frequently used method of testing your BAC in Arizona DUI cases is blood testing. As a general rule, blood testing is more precise and less prone to attack with a successful defense than breath testing. Whenever an Arizona DUI suspect refuses to take a breath test, the police officer has the option of obtaining a search warrant and forcibly taking the defendant's blood.
Who Takes The Blood?
Because it's up to the law enforcement officer to choose which test to administer: in Phoenix, Tempe, and Glendale, the police usually use the Intoxilyzer 8000 for an alcohol breath test. In many East Valley communities, including Scottsdale, Mesa, Gilbert, and Chandler, the police prefer to administer a blood test, either at a hospital or at the police station. TIP: insist on a hospital, and never sign a Waiver of Liability. Police stations are not even close to ideal clinical settings, and police officers are not trained nurses.
Does The Manner In Which The Blood Is Obtained Matter?
Absolutely! A defective blood draw has the potential to not only harm the subject, but to pollute the sample as well. Improper methods can result in an erroneously inflated BAC result of more than .20 (which can take a sober diabetic into the realm of an extreme DUI).
Arizona Breathalyzer Background
Alcohol intoxication is legally defined by the BAC level. However, taking a blood sample in the field for later analysis in the laboratory was not practical or efficient for detaining drivers suspected of driving under the influence (DUI). What was really needed was a way to measure something related to BAC without invading a suspect's body and consequential constitutional rights. Urine tests for alcohol proved to be just as impractical in the field as blood sampling. In the 1940s breath alcohol testing devices and machines were first developed for use by police. In 1954, Dr. Robert Borkenstein of the Indiana State Police invented the Breathalyzer, one type of breath alcohol testing device.
How do Breathalyzers Work?
We hear and read about drivers who are charged with a DUI arrest after an accident, and usually a news report on the accident will state the driver's blood alcohol level as well as what the legal limit is for blood alcohol. But what do those figures mean and how do police officers find out if a driver they suspect has been drinking is legally drunk? You have probably heard about the Breathalyzer, but may wonder exactly how a person's breath can show how much that person has had to drink.
Principle of Testing
Alcohol that a person drinks shows up in the breath because it gets absorbed from the mouth, throat, stomach and intestines into the bloodstream. Alcohol is not digested upon absorption or chemically changed in the bloodstream. As the blood goes through the lungs, some of the alcohol moves across the membranes of the lung's air sacs (alveoli) into the air because alcohol will evaporate from a solution -- that is, it is volatile. The concentration of the alcohol in the alveolar air is related to the concentration of the alcohol in the blood. As the alcohol in the alveolar air is exhaled, it can be detected by the breath alcohol-testing device. So instead of having to draw a driver's blood to test his alcohol level, an officer can test the breath on the spot and determine whether there is a reason to make a DUI arrest.
Because the alcohol concentration in the breath is related to that in the blood, you can figure the BAC by measuring alcohol on the breath. The ratio of breath to blood alcohol is 2,100 to 1. This means that 2,100 milliliters of alveolar air will contain the same amount of alcohol as 1 milliliter of blood.
The legal standard in DUI law for drunkenness across the United States was 0.10% for years, but recently many states have adopted the 0.08% standard. The federal government has pushed states to lower the legal limit. The American Medical Association says that a person can become impaired when the blood alcohol level hits 0.05%. The standard 0.08% means that there is 0.08% gram of alcohol per 100 milliliters of blood.
Arizona Breathalyzer
The Intoxilyzer is generally considered one of the best breath testing machines available today and is also the most commonly used machine in Arizona. However, it is not without problems. It must be properly maintained and operated in order to function accurately. Even when functioning properly, it may have an inherent margin of error of plus or minus .01.
The Intoxilyzer uses infrared spectrometry to measure the degree the alcohol in a breath sample absorbs infrared energy. The greater the amount of alcohol present in the sample being analyzed, the greater the absorption. Inside the machine a quartz lamp radiates infrared energy through the sample. The amount of energy that makes it through the sample (and is not absorbed by alcohol) is then measured and calculations are made.
If you've been arrested for a DUI in Arizona and have failed a chemical test, don't despair. There are ways to challenge the results, even in the case of an extremely high result.
Field Sobriety Tests
Almost every DUI case in Arizona includes evidence of field sobriety testing ("FST"). FST's such as the One Leg Stand, Walk and Turn, and Horizontal Gaze Nystagmus (Eye Test) rank as an officer's best tools in establishing probable cause and securing DUI convictions.
THESE ROADSIDE FIELD SOBRIETY TESTS ARE COMPLETELY VOLUNTARY AND SHOULD BE POLITELY REFUSED
In case you wondering, the absolute best thing you can do to help the police build a DUI case against you is take the FSTs?
"Field sobriety testing" in Arizona is not an effective means for determining a person’s level of impairment or intoxication. No conclusive studies link the results of any field test to legal intoxication. The best studies show less than an 80% rate of accuracy!
Out of the numerous different FSTs out there, only three of the tests available to officers have been given any shred of "scientific" legitimacy by the National Highway Traffic Safety Administration (NHTSA). These tests include:
- The Horizontal Gaze Nystagmus Test
- The Walk and Turn Test
- The One Leg Stand Test
No other tests given in Arizona are validated in any official way! In fact, many of the tests involve closing your eyes and balancing. Without a visual frame of reference, no "balance" test can honestly claim to measure sobriety, impairment, or intoxication. Therefore, tests such as the Finger to Nose Test, and the Rhomberg Balance Test should be avoided.
Other tests, such as counting backwards, or saying the ABCs backwards, counting your fingers, or playing "pattycake" have no correlation whatsoever with your ability to operate a motor vehicle safely.
Officers regularly testify that FSTs are gauged to measure "divided attention." For instance, when you drive, you must divide your attention between several tasks, such as steering, breaking, navigating and signaling. The theory is that alcohol impairs one's ability to divide attention.
Again, you have the absolute right to politely refuse to submit to field sobriety testing. If you decide to take the tests then you subject yourself to the officer’s own interpretation of your performance on those tests. The officer is already investigating you for a DUI and has most likely already made up his/her mind as to your guilt, and in all likelihood will arrest you even if you take the FSTs.
Disadvantages In Refusing The Field Sobriety Tests:
The common perception is that refusing to submit to field sobriety testing will result in the suspension of your driving privileges. This is FALSE. Unless you are on probation and/or have another case pending in which a Judge has ordered you not to refuse to take the tests, you have the absolute right to refuse to submit to field testing. You must submit to a chemical test (i.e. blood, breath, or urine) – NOT FSTs. The biggest, and somewhat ludicrous, drawback of refusing these tests is that the prosecutor will argue that you refused out of a "consciousness of guilt." The prosecutor will try to make the Jury believe that you didn't take the tests because you knew you were drunk and would fail them.
The only other major disadvantage is that the officer will probably arrest you right away. Usually, refusing to submit to FSTs just speeds up the inevitable arrest. The officer might also threaten that if you don't take the tests, you will be booked into jail. If threatened by the police, then agree to submit to the FSTs; just make sure that you let the officer know you are cooperating out of respect for him/her, but you are only submitting to these FSTs under protest due to threats. Of course, you want to make sure this gets into the officer’s notes. That way, your DUI attorney can later make a motion to suppress the tests.
