Challenging Breath Test Results

Effective & Aggressive Charlotte DWI Attorneys

DWI charges are intimidating to a lot of folks. Having to fight the state of North Carolina in a courtroom can be a scary prospect. Make no mistake, the state is intent on obtaining a conviction, and DWI convictions are not pretty. The repercussions of a DWI conviction can be severe. At Dummit Fradin, our mission is to provide peace of mind for our clients, and we feel the best way to do that is to offer you the information you need to understand what's happening. You do have defense options, and the more you know about your DWI lawyer's potential defense strategies, the better.

Call (800) 507-7494 to schedule a free initial consultation.

What the State Needs to Prove

There are several things the state has to prove to obtain a DWI conviction. It's not enough for the state to just show that you were the driver of the vehicle. Or that you were on a highway or public vehicular area, or even that you had been drinking (unless you're under 21).To obtain a DWI conviction, the state must also show that you were impaired as a result of your drinking.

Now, obviously, we can't get inside of other folk's brains to personally experience their thought processes or their changes in reaction time. So there's no real objective way to measure impairment. Each person can experience different degrees of impairment even if they consume the same amount of alcohol. In fact, two people with the exact same alcohol concentration in their blood will have different levels of impairment. This reality, though, could make proving impairment in DWI cases tough for prosecutors. In the absence of any objective way to measure impairment, every DWI case could become embroiled in a battle over whether the defendant was unable to perform basic bodily functions. To help prosecutors with this problem, the General Assembly passed an either/or standard for obtaining convictions in DWI cases.

Under this standard, a person is guilty of DWI if driving either:

  • Appreciably Impaired from an impairing substance, or
  • After having consumed enough alcohol to have a blood alcohol content of .08 or greater

Because proving impairment is tricky, the authorities have made BAC the preferred route for DWI conviction. If they can get the right BAC number, they can convict you. It doesn't matter if you show physical evidence of impairment or not.

In North Carolina, the way they get this number most of the time is either through a machine called an Intoxilyzer 5000 or an Intox EC/IR II. It's one of many breath analysis machines on the market, but currently, they're the only breathalyzer machines approved for use in North Carolina's courts. (The state can also calculate blood alcohol content by a blood test, and often relies on them in cases involving accidents.) To adequately defend your DWI case, your DWI attorney should be very familiar with how the Intoxilyzer 5000 or Intox EC/IR II works and how the test is administered. Only then can your DWI defense lawyer raise issues that can throw doubt upon the results, if not disqualify them entirely.

How DWI Breath Tests Work

Both the Intoxilyzer and Intox tests work on similar, yet different, principles. In the body's digestion and circulation system, ethyl alcohol (the type of alcohol we drink, also called ethanol) remains unchanged. It, in its original, non-metabolized form, affects the central nervous system in ways we're all familiar with.

While the alcohol is still in the bloodstream, the blood passes through the lungs. Some of this alcohol is passed out of the bloodstream into the air sacs in the lungs called alveoli. In a breath test, this air that has some alcohol in it, or alveolar air, is exhaled by the suspect into the machine, which measures the amount of alcohol in the breath.

However, the amount of alcohol in 1 milliliter (mL) of alveolar air is not the same as the amount of alcohol in 1 mL of blood. These two amounts are directly proportional, though, meaning that as the amount of alcohol in the blood increases, so does the amount of alcohol in the alveolar air. We can see this conceptually by thinking of the alcohol (C2H5OH) molecules bouncing around in the bloodstream along with carbon dioxide (CO2) and oxygen (O2) molecules. (All molecules are moving around rapidly.)

The job of alveoli is to exchange all kinds of gases in the blood. For the most part, CO2 leaves the bloodstream and O2 enters. Ethyl alcohol is volatile, meaning that it tends to become a gas when it's dissolved in liquid. Thus, when the alveoli are pulling gases out of the blood, the ethanol is one of those gases. As the number of alcohol molecules in the blood increases, the alveoli pull more alcohol out of the bloodstream. This alcohol that goes into the alveoli is breathed out in the alveolar air and is then measured by the Intoxilyzer 5000 and Intox EC/IR II.

The average ratio of alcohol in alveolar air to alcohol in blood is 2,100:1, called a partition ratio in the law. This ratio is, of course, just that - an average. According to Dr. Srikumaran K. Melethil, Professor of Pharmacology at the University of Missouri at Kansas City, the ratio can range from 1,900:1 to 2,400:1, and the value of 2,100:1 was picked by a panel in 1972. Everything from body temperature to the composition of the particular test subject's blood to physical activity can affect a person's partition ratio. Unfortunately, because the ratio is defined by state law, there's no purpose in arguing that yours is different or that the conditions changed your partition ratio.

The Intoxilyzer 5000

The Intoxilyzer 5000, made by CMI, Inc., is a breathalyzer machine that uses a technology called infrared spectroscopy or infrared spectrophotometry. The basic premise behind infrared spectroscopy is that different types of molecules absorb various wavelengths of light differently. Given how much light ethanol is known to absorb at different wavelengths, how much light at those wavelengths we shine into a sample of air containing ethanol, and how much light remains at those wavelengths after it's been shined through the sample, we can determine how much light was absorbed by the sample and thus how much ethanol is in the sample.

The air you blow into the Intoxilyzer is collected in a chamber. A lamp designed to give off specific wavelengths of light is shined through your breath onto a lens. The lens focuses down the light onto a series of filters, each one highly selective for a particular wavelength of light. The light that remains after the filtration is detected by a photosensor, a sensor that detects and quantifies the amount of light hitting it. Given the amount of light hitting the photosensor at each wavelength, the computer in the Intoxilyzer 5000 determines the amount of alcohol in the sample, and thus, using the 2100:1 partition ratio, the amount of alcohol that is in your blood.

Many Intoxilyzer 5000s are still in use in North Carolina, but no police, sheriff, or highway patrol department is buying any more of them. They are still approved for use and, as long as the rules for calibration and performing the test are followed, the results from them are still admissible in court. The state is switching over to the Intox EC/IR II.

The Intox EC/IR II

The Intoximeters, Inc. Intox EC/IR II is the newer instrument approved for use in North Carolina. This instrument uses fuel-cell technology. (The Alco-Sensor models work on the same technology.) The air that you blow into an Intox passes into a chamber and through a porous electrolyte layer between two platinum electrodes. The platinum electrodes oxidize any alcohol in the breath into acetic acid (CH3COOH). In the process, free protons and electrons are produced. The electrons are drawn down a wire, through a meter measuring the electrical current (the flow rate of the electrons), then to the other side of the fuel cell. A computer takes the output from the current meter and can calculate the amount of alcohol in the breath. State law requires that, in order to be admissible in court, all breath tests must be done in accordance with specific procedures designed by the Department of Health and Human Services. Those regulations are described here.

After you arrive in the breath test room, the BT (breath test) operator (called the "chemical analyst" by the state) types in your:

  • Name
  • Date of birth
  • Sex
  • Driver's license number

The citation number for your DWI ticket is also typed in, along with the name of the arresting officer, and the name and permit number of the breath test operator. All this will be printed out at the top of the slip of paper the machine produces with the test results.

If you were arrested for driving while impaired by a trooper, you may well be tested by that same trooper, because highway patrol members generally are certified to operate the Intoxilyzer. Most police and sheriff's departments use separate operators because most of their personnel are not trained and certified on the machine.

What Happens Before the Test

Before you take the test you must be observed for 15 minutes. You are instructed to remove all foreign objects from your mouth. This includes chewing tobacco, gum, mints, even dentures and bridge work. They can trap and absorb alcohol and give a falsely high reading if you blow with them in your mouth. During this 15-minute period, you are to put nothing in your mouth, nor burp, hiccup or vomit. This is to ensure that the machine measures the alcohol content in your deep lung air and not any residual alcohol in your mouth. In theory, 15 minutes is how long it takes for the natural process of secreting saliva to wash any residual alcohol from your mouth. Burping, hiccupping or vomiting would bring up stomach gases saturated with alcohol that could remain in your mouth, which could inflate the test results.

An officer is supposed to observe you this entire 15 minutes to make sure the proper procedures are followed. During this time you are read and given a written copy of your rights with regard to the test. This includes your right to refuse the test, the penalty for refusing (automatic one-year suspension of your driver's license) and your right to have an attorney or some other witness present when you take the test.

If you request a witness, you're entitled to make telephone calls and the state is required to give the witness up to 30 minutes to get there. The breath test operator or the DWI arresting officer will log on the breath test slip the exact time that you were read your rights, whether you requested an attorney or witness, and the time you called the witness or attorney.

Confirming Calibration

When the observation period is up, the breath test operator will draw blank air into the machine and test it. It should come up with .00. Then the breath test operator runs a calibration check with a test solution. The machines have pressurized canisters with a .08 infusion. Air inside the beaker is sucked out and analyzed to check the calibration of the machine. (The "calibration check" is not conducted through the breath tube that you blow in. It enters the machine through a separate port, leaving no means of measuring possible contaminants in the breath tube.) The time when each of these steps was performed is also logged on the breath test slip. After the calibration check, the machine is purged and a new air blank drawn to ensure that no residual alcohol from the calibration check is contaminating the chamber. (Again, this is done through a separate opening and not through the breath tube.)

If everything checks out properly, you are then instructed to blow long and hard into the instrument's mouthpiece, until it buzzes. The instrument will analyze your breath and print out your calculated blood alcohol content. The instrument is purged and another air blank tested. Then you are instructed to blow a second time into the machine. This is because state DWI law requires two readings from the instrument. In order to have some assurance that the machine is reading your breath consistently, the law requires that the readings be within .02 of each other, and that they be consecutive.

When Test Results Vary

If the second test doesn't come within .02 of the first, you can be ordered to blow as many additional times as necessary to come up with two acceptable readings or until the breath test operator concludes that the machine is not working right. Again, the time for each of these steps is logged on the breath test slip when it prints out.

As we discussed earlier, the instrument is not very accurate. The two consecutive tests could be .08 and .10, a 25 percent variation, and you could still be convicted. This 25 percent variation is built into the system and is acceptable to law enforcement and expected by scientists. It is not acceptable under the Constitution, and it should not be acceptable to the courts.

There is one exception to the two-test requirement. If you blow the first time and then refuse to blow or are unable to blow the second time, the state is allowed to use that sole reading in court, and it will be accepted. Furthermore, you will be recorded as having refused to take the test and lose your license for a year. It's the worst of all worlds. So if you blow once, blow twice, no matter how high the instrument says your blood alcohol content is.

Fighting the Results in Court

There are two general routes for attacking breath test results in court. First, you can try to get the results thrown out for failure to follow proper procedures. Second, you can attack the results as being unreliable because of specific factors involved in your test. As a rule, you're more likely to succeed in getting the test disqualified for failure to follow proper procedures.

Failure to Follow Proper Procedures

In order to disqualify the breath test for law enforcement's failure to follow the procedures required by the law, first, your attorney should force the state to prove that the breath test operator was properly trained. The odds are that the operator is trained, or else he or she would not have been administering the test, but you don't have to take the state's word for it. Require the operator to produce his or her training certificate. If the operator doesn't have it, you can move to suppress the results.

You should also make sure the operator followed the proper procedures in administering the test. Did someone watch you the entire 15 minute waiting period? That's often not the case when the arresting officer is also the breath test operator, since most operators have to look down at the keyboard while typing in your name and other information. While they're looking down, they're not observing you burping or hiccupping.

Were you advised of your rights? Were you coerced into waiving the right to have a witness? It's not unknown for an officer to say something like, "It's 2:00 in the morning. Do you really think your attorney will appreciate being dragged out of bed for a routine breath test?" If you requested a witness, were you allowed the full 30 minutes for a witness to arrive? Was the witness allowed back into the room to actually see you take the test? Often, witnesses arrive but aren't allowed past the front desk to go into the back room, off limits to the public, where the test is administered. You have a statutory and constitutional right to have a witness present. If the witness is denied admission to the testing room, or if the person at the desk just didn't take the witness back to the room because he/she didn't specifically say that they were planning to be a witness, you have solid grounds for suppressing the test, as we discussed in Chapter 3, but be prepared for a fight. The authorities will claim that your witness didn't arrive in time. Under the court's ruling in State v. Ferguson, the burden will be on you, the accused, to prove that your rights were violated in this manner.

Grounds for Suppressing DWI Breath Test Results

In Superior Court, the operator must testify in person. Regardless, force the state to prove in court that the machine was properly calibrated and had been properly maintained. Ask to see the maintenance logs. Some counties will not let you see the logs without a subpoena. Your attorney may elect to look at the 20 or 30 tests administered before and after you took your test. Look for any sign that the machine may not be working reliably, such as unacceptable variation in consecutive readings on samples from the same person, or instances in which the machine was shut down because it was not functioning properly. To review all of these documents most DWI lawyers charge additional fees. If there are no grounds for disqualifying the test on procedures, there may be grounds in the specifics involved in your test.

False Breath Test Results

Remember, the machine is supposed to disregard the air you expel at first in order to capture deep lung air. But there are many ways that the machine can be thrown off, resulting in a falsely high reading. Many people puff their cheeks as they blow, and they may not unpuff their cheeks until well after the machine has started capturing air for analysis. If this happens, the air inside the mouth will be included in the sample that is measured. This air typically has a higher alcohol concentration, since alcohol is consumed through the mouth. Thus, the residual mouth air, which doesn't have the same concentration of alcohol as the alveolar air that the breath test instrument is designed to be measuring, will give an incorrect test result that is higher than the actual blood alcohol content.

The machine may also be inaccurate if your salivation is suppressed for any number of reasons. As many as four million Americans, mostly women, have Sjögren's Syndrome, pronounced "show-grins syndrome." Their glands do not secrete fluid regularly, be it their tear ducts in their eyes or their saliva glands in their mouth. The primary symptom of the disease is frequent dry mouth. Because people with Sjögren's Syndrome do not salivate regularly, the 15-minute waiting period before administering the test is not long enough for saliva to flush out any residual mouth alcohol. Their tests will read this mouth alcohol and be inaccurate and too high.

Likewise, some medications can produce cotton mouth or dry mouth as a side effect. The impact on your breath test is the same; the results can be skewed too high. If you were taking any medication at the time of your arrest, you should tell your attorney. If you were taking medications (either prescription or over the counter) that don't tend to produce cotton mouth, tell your attorney about them anyway, even if it's only aspirin. Your attorney may know or may be able to find out side effects of these medications that can affect your absorption rate of alcohol or your partition ratio and skew the results. Simple aspirin thins the blood, for example, and could increase your partition ratio.

Things that Can Influence Breath Test Results

If you burped, hiccupped, vomited or regurgitated even slightly during the 15 minute waiting period and the breath test operator didn't restart the waiting period, the test was not administered according to procedure and may be inaccurate. This should be grounds for challenging the results. People with ulcers are especially liable to have reflux that will throw off the results.

If the testing officer didn't notice that you had a small quantity of chewing tobacco in your mouth during the waiting period or when you took the test, the test results could be inaccurate. If you have unusual cavities in your mouth, such as a hole in your gum caused by a missing tooth, you should let your attorney know. These can trap residual amounts of mouth alcohol that may not be forced out until you make the strong blowing effort required to fill the machine.

Finally, if you were wearing dentures or a bridge and did not remove it, the test may be thrown off. Residual alcohol may be trapped between the gum and your dentures, or be absorbed into the foamy adhesive of your dentures. Sometimes people take the test with their dentures in because they don't know better. They're told to remove all foreign objects from their mouth, but they don't think of their teeth as a foreign object. Vanity may also play a role. Some people lie about wearing dentures because they don't want to be seen without them.

Need a DUI Lawyer in Charlotte? Turn to Dummit Fradin.

As you can see, a strong DWI defense can make all the difference in your drunk driving DWI case. You have rights worth protecting, and when you need an experienced, informed DUI DWI attorney, the doors at Dummit Fradin are open.

For more information, please give us a call today.

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