Reliability of DUI Testing
There are two main types of tests that may be administered in conjunction with a DUI (driving under the influence) offense: field sobriety tests and chemical tests. Field sobriety tests are administered after a driver is pulled over and are used by a police officer to establish probable cause that the driver is intoxicated, therefore enabling the officer to make a DUI arrest. Chemical tests are administered after a driver is arrested for suspected DUI. Typically either a breath test or blood test, these tests are used to determine whether the driver has an unlawful blood alcohol concentration (BAC).
Field sobriety test and breath/blood test results will play an important role in enabling a prosecuting attorney to build a strong case against a defendant who has been charged with DUI, however, many times the evidence can be successfully disputed.
Challenging the Breath/Blood Test
In California, a breathalyzer test or a blood test may be administered to determine a driver's blood alcohol concentration. If it measures at .08% or higher, the driver is considered to be "under the influence" and may face DUI charges. These chemical tests have inherent faults and, if administered improperly, may yield incorrect results. Some of the factors that we may look at in challenging a breath or blood test include:
- Whether the test was administered by a trained and qualified professional
- Whether the test was administered exactly per protocol
- Whether the breathalyzer was properly calibrated and maintained, in accordance with state standards
- Whether the driver was observed for the allotted time period prior to the breath test to ensure he or she did not drink, belch, vomit, smoke or eat
- Whether the blood sample was mishandled
- Whether the blood sample was properly mixed with preservatives and anticoagulants
Questioning the Accuracy of Field Sobriety Tests
Field sobriety tests are particularly unreliable as they are more easily affected by physical injury, illness, age and weight. Even the shoes that a driver is wearing may affect performance on field sobriety tests. Some of the factors we may look at in challenging field sobriety tests in a DUI case may include:
- Whether the tests were administered properly
- Whether the officer who administered the tests was trained and qualified
- Whether the officer's analysis of the tests was accurate
- Whether a non-alcohol related factor may have influenced the driver's performance on the tests (high-heeled shoes, old age, weight, physical injury, nervousness, pre-existing medical conditions, etc.)
In handling DUI cases for our clients, we look at testing from every possible angle to determine how to best challenge results. True, you may have been told that you performed terribly on field sobriety tests. You may have taken a breath test that showed a result of .12%. This does not necessarily mean that the tests were accurate or that you should be convicted.
Understanding the Blood Test
It is illegal to drive in this state with a blood alcohol content (BAC) of 0.08% or higher if you are an adult or 0.01% if you are under 21. There are a number of tests that can be administered when an officer pulls a car over on the side of the road. They may involve basic standardized field sobriety tests, or may more inquisitive ones such as a breathalyzer or blood test. Blood tests are administered to individuals suspected of driving under the influence of alcohol or drugs and they asses the level of alcohol within the suspects system. By obtaining a license in the state, applied consent is given for testing in the event of a lawful arrest for drunk driving.
Blood Collection Law
Title 17 of the California Code of Regulations states a number of techniques that need to be adhered to during blood testing. Samples must be taken by venipuncture as soon after the alleged incident as possible. A trained technician should be the one to draw the blood, since errors during this process commonly lead to insufficient samples. The site should be properly sterilized to prevent contamination and alcohol should not be used since it can add to the level of alcohol found within the individuals system. Any samples taken need to be properly stored or else the evidence obtained may become altered. Samples should also be mixed with an anticoagulant, as well as a preservative. There are many mistakes that can be made in a blood test that may render the sample insufficient.
Challenging Blood Test Evidence
The results of DUI testing, including blood tests, can frequently be incorrect due to improper administration or other mistakes. Some of the more common types of problems found in blood testing include:
- Using testing kits that have expiredImproperly mixing chemicals
- Inadequate skin cleaning before the draw
- Blood contamination during the draw
- Administration of the test by an unqualified person
- A DUI blood draw should always be tested by an independent laboratory to validate the government's findings, or to show that the test was inaccurate and should not be used as evidence in the case.
Preliminary Alcohol Screening (PAS) Test
Preliminary alcohol screening (PAS) has been the subject of much debate. Also referred to as preliminary breath test (PBT), this refers to the instruments used by police to conduct preliminary tests in order to determine an initial indication of alcohol present in the blood.
It is crucial to remember that, if you are over 21 and not on probation for DUI, this PAS test is completely voluntary. The police are supposed to advise of the voluntary nature of this test but often times they simply do not. California Vehicle Code section 23612 authorizes an arresting officer to use the handheld PAS device to determine the level of alcohol in a driver's blood. However, this statute also states that the PAS test is voluntary and the officer is “required” to advise the motorist that the test is voluntary.
While some tests only detect the existence of alcohol (these “flashlight” sensors essentially detecting if there is any present, but not how much) most commonly they are used to determine a specific level of alcohol in the blood. There are two types of PAS devices that accomplish this: fuel cell devices and Taguchi gas sensor devices.
Fuel cell devices work by electrochemically oxidizing ethanol in the subject's breath. The electrical current created by the process is then measured and the resulting reading gives the officer an indication of the amount of alcohol present. However, there are many inherent problems with these devices, namely the lack of specificity. Specificity merely refers to the fact that these devices, while working to detect the presence of ethanol, have also been known to show similar results at the presence of a variety of other chemicals. Researchers have found acetaldehyde, methanol, isopropanol, and n-propanol have all reacted positively to tests while using the Alcometer Pocket Model. Aside from specificity, there is an array of other issues that can cause false positives. For instance “mouth alcohol” can result in artificially raising the levels of alcohol in the breath. If the test has been administered recently after a burp, belch, or vomiting, the PAS can detect more ethanol in the breath than is actually impairing the individual. As such, a 15-20 minute observation period is necessary to ensure that no burping or similar acts have occurred to result in extra mouth alcohol. However this is uncommon during Field sobriety tests (FST). Other issues, such as oxide buildup improper care for units, how recently the unit was used (an issue in sobriety check points) and battery life has also been known to skew test results.
The Alco-Sensor III, along with Alco-Sensor IV and Alcotest 7410 Plus, are the most commonly used devices by the California Highway Patrol. The Alco-Sensor III has even been deemed insufficiently accurate for use as evidentiary testing.
Along with fuel cell devices, the Taguchi gas sensors are also commonly used. Chemicals in the sensor are attracted to alcohol and result in increased electrical conductivity. The two types of units are active and passive gas sensors. The passive units (the aforementioned flashlight tests) merely take readings off of the air around the subject. This is typically accomplished by sticking the officer's “flashlight” into the car to read a driver's license, and the device detects alcohol in the air. This creates obvious issues, since it often detects a variety of things other than alcohol in the driver, such as alcohol from passengers and other products like aftershave and perfume. Both active and passive tests have the same issue with specificity as fuel cell devices, as both have been known to test positively for other compounds other than ethanol. Lastly, temperature also affects readings for both active and passive units.
Though these tests are typically used as a preliminary indication of the presence of alcohol, this often will bias an officer's judgment on subsequent FST. California is currently moving towards adopting a single handheld device for all evidential breath tests, eliminating the current machines found in police stations. This will possibly provide new angles for counselors to explore, given the unreliable nature of the devices and the skepticism from most jurors towards these handheld devices. For instance, an analysis of the Alcotest 7410 Plus, the device currently being purchased for this purpose, has been found to have specific faults, namely a lack of mouth alcohol detectors, no RFI detector (meaning problems can arise from officers radio transmitters and walkie-talkies), and as previously mentioned these fuel cell analysis devices do not detect only ethanol. Finally, this single, seemingly simpler device will be replacing much more complicated machinery.
The Walk-and-Turn Test
In combination with Horizontal Gaze Nystagmus (HGN) and the One-Leg Stand (OLS) , the Walk-and-Turn (WAT) test is used to determine the level of impairment from a subject. This, along with the OLS, is considered to be a divided attention test. This is because a subject must listen to instructions while performing the movements at the same time. For someone who is impaired, dividing the attention between the two tasks can be near impossible. Research shows that 79% of subjects who take the WAT test who show two or more of the indications of a failed test will be over the legal limit.
Guidelines of the Test
To administer the test, the rules are simple. The subject must take nine steps with heel-to-toe on a straight line. After the last step, they must turn on one foot and return in the same manner to the point that the test began. There are eight indications that are considered to be red flags for impairment. These include the following:
- Inability to keep balance while listening;
- Beginning the test before instructed to do so;
- Stopping to regain balance;
- The heel not touching the toe;
- Stepping off of the line;Using arms to keep balance;
- Turning improperly; and
- Taking an incorrect amount of steps
If you have recently been criminally charged and were administered a WAT test, it is important that you remember that a failed test does not equate to a criminal conviction. Just because you were told that you fail the test does not mean that you will ultimately be found guilty. Keep in mind that combined with the other two standardized tests, there is only a 90% level of accuracy. Unfortunately, extenuating circumstances and factors, such as medical conditions, can all contribute to a subject appearing to fail, even if they are stone cold sober.
DUI Horizontal Gaze Nystagmus Test
When looking to determine the level of impairment of a driver who is suspected of driving under the influence, many law enforcement officers will administer a field sobriety test. This is a test that looks to the physical and mental abilities of the defendant to determine how impaired they are from alcohol usage. The problem, however, arises when one considers that this is a test with no objective results. Instead, it is a subjective test with opinionated conclusions. To help in creating standards for these tests, the National Highway Transportation Safety Administration has created guidelines for how these should be administered. One of the most popular includes the Horizontal Gaze Nystagmus (HGN).
To understand the HGN test, one must understand nystagmus. Scientifically speaking, nystagmus refers to the involuntary jerking of the eye when the inner ear is disturbed. HGN therefore refers to this jerking when it occurs in a horizontal pattern. The reason that the NHTSA uses this as a field sobriety test is that it is believed that alcohol consumption can cause the eye to bounce laterally, with the amount of the jerking to increase with the amount of alcohol in the body's system.
This is typically referred to as Alcohol Gaze Nystagmus and is due to the fact the alcohol can affect the motor control systems of the body. This results in instability and poor motor coordination, which can in turn affect the ability of a person to smoothly control their eye movements. When the nervous system is affected, the eyes can be unable to remain steady and can have an observable effect.
To administer the test, the officer will place the subject in an area with good lighting, although they are not permitted to be facing blinking lights or oncoming traffic as this could disturb the ultimate results of the test. The officer will then use a flashlight to point towards their face. The subject is then asked to follow the tip of a pen with their eyes which is placed from twelve to fifteen inches from their eyes. Should there be a lack of smooth eye movement or distinct jerking, the subject could fail the test.
Although this is a standardized test from the NHTSA, it does not mean that it is without flaws. Should the test be administered by a police officer that is not properly trained or if the officer makes a subjective decision based solely on opinion, you should not be forced to suffer from the results. In fact, in some courts, the HGN test is not admitted as evidence as it can be believed to be insufficient.
The One-Leg Stand
In an effort to make field sobriety tests as accurate as possible, the National Highway Traffic Safety Administration has put together three standardized tests that, when used correctly together, give the best possible chance of accurately determining the level of intoxication of the subject. One of the most used types of tests is that of the One-Leg Stand. As one of the two divided attention tests, the process of the test is actually pretty simple.
What an Officer Observes
To administer the test, the subject is asked to stand still with one foot raised six inches from the ground. While the foot is in the air, the subject must count by thousands while the officer times them (typically to 30 seconds). There are four different indications that a law enforcement officer will be looking for that will serve as red flags. These include:
- Swaying while trying to balance one's self;
- Using arms to achieve balance;
- Hopping to maintain balance; and
- Putting foot down during the test
Research provided by the NHTSA proves that over 83% of people who take the test and have two of the above indications will be over the legal limit for BAC. This, however, is not foolproof and does not mean that everyone who "fails" is actually intoxicated. Extenuating factors and details regarding the subject can all play into an inability to complete the test without failing.
By choosing to work with us, you are putting the experience of a heavyweight in your corner. We have a full-bodied understanding of criminal law and are prepared to help our clients in every way possible as they face DUI-related charges. So don't waste another moment! When you have this much on the line, you need to be confident that you are doing everything possible to protect yourself. Get us involved and rest easier knowing that you will no longer have to face it alone. We will be there to fight for you.
Breathalyzer Testing and Refusing it
One of the common tests given to a driver in a DUI case is a breathalyzer test. The purpose of this test is to establish your blood alcohol content (BAC) level, and whether or not you were driving under the influence. Drivers with a BAC of 0.08% or higher, or persons under 21 with a BAC of 0.01% or greater, are considered legally intoxicated. Breath test results are used in court as evidence of intoxication in your DUI case.
DUI consequences can include probation, jail time, fines, restitution, alcohol and/or drug treatment, community service and license suspension or revocation. In cases involving a BAC of 0.16% or higher, the sentencing can be especially severe. There are various ways that test results can be challenged that could result in the evidence being suppressed.
Refusing the Breath Test
Under state's implied consent law, if you are driving in the state you are required to take a breath test upon being lawfully arrested. Law enforcement will carry a handheld Preliminary Alcohol Screening device allowing them to carry out a test even on the side of the road. This test is not required under the law for those 21 or older. Refusal may be done by remaining silent, not completing the test or refusing it even if you were only asked once. Your driver's license can be suspended from six months to a year if you refuse to take a breath test, in addition to the other penalties that can be faced if you are convicted. After refusal, a DMV hearing may be requested in which it will be necessary to demonstrate if the arrest was lawful, if there was reason to suspect you of drunk driving, if the officer properly communicated the outcome of refusal and if you did in fact refuse.
Errors During Testing
Breath test results can be extremely inaccurate if the machine wasn't well maintained, standard procedures weren't followed in administering the test, or the person operating the testing equipment wasn't properly trained. We can evaluate your breath test results and dispute the testing if:
- The equipment used in testing wasn't properly maintained
- Testing procedures were not followed, or were altered in some way
- The person administering the test wasn't sufficiently trained or qualified
There may be other reasons that resulted in improper testing that we will also explore. You can count on our office to aggressively defend your rights at all times, and provide skilled representation during legal proceedings.
Causes of False Breath Tests: "Mouth Alcohol"
One of the largest causes of false or inaccurate breath tests is the presence of "mouth alcohol." This alcohol "destroys" the accuracy of the breath being expelled from the lungs as the subject is breathing in the device. The issue is that the devices assume that the breath being tested comes from the lungs. In order to determine the blood alcohol level, the devices use the "partition" ratio of 2100:1.
This is a rough average of the ratio between alcohol in one's breath compared to blood. Therefore the alcohol present in the mouth that doesn't come from the lungs is being wrongly multiplied and skews the reading. There are many ways mouth alcohol can be present, namely if the subject has been eating, drinking, smoking, or burped, hiccupped, and / or regurgitated within 15-20 minutes of the test.
Mouth alcohol is essentially unprocessed alcohol that is expelled from the stomach and is then retained in the tissue of the esophagus and mouth. This is then carried by the air from the lungs and read by the device. Since it is unprocessed, this has a higher concentration than actually present in the blood, which is why the 2100:1 ratio would not be accurate and the resulting reading untrustworthy.
Challenging DUI Evidence & Breath Test Results
As previously stated, there needs to be 15-20 minutes of deprivation and close observation for the test to be accurate. However, this is almost never the case. During cross-examination, an experienced Los Angeles DUI lawyer can usually determine that during the required observation period, the officer was also doing other tasks, such as paper work, setting up the machine, and other tasks that cause the officer to lower their head. This raises, at the very least, the possibility of doubt that the test may have been contaminated by mouth alcohol.
Another issue is that many common household products contain levels of alcohol. Mouthwash, cough syrup, and breath freshener all contain some amount of alcohol. People, and especially jurors, are often surprised but the amount of alcohol actually present, ranging from around 6% to in excess of 70%. Though the rare case, a lot of products have alcohol content of around 15-20%. This is then retained inside the mouth and expelled with the air from the lungs.
In a test of subjects that used Listerine for 30 seconds, after one minute the average BAC was recorded at .43% and after five minutes was still over the legal limit (.08%). Dentures and other dental appliances cause the biggest problems, since they capture alcohol in the oral cavity and significantly raise the amount of alcohol present in the mouth. During one test, which used a dental adhesive inside the subject's mouth, determined an immediate amount of ethyl alcohol as .48%, well into the lethal range.
After more than half an hour, the subject still tested above the legal limit at a BAC of .112%, despite the miniscule amount of alcohol ingested. Perhaps most staggering was the testing on Binaca throat spray. Using various amounts sprayed into the mouth, the BAC ranged from .034% all the way up to .811%. Given that the lethal range is defined usually anywhere from .25-.40% or higher, this number is nearly inconceivable and obviously inaccurate.
Researchers have, however, found that consistently washing the mouth before the test can reduce the presence of mouth alcohol. They also concluded cold water is more effective than warm water. The police NEVER offer the opportunity for the subject to rinse out their mouth with water. Why would they? The higher the reading, the better for their report!
Other issues also cause the presence of mouth alcohol. Blood in the mouth, as is the case among many accidents, causes a higher concentration of alcohol than the air from the lungs. Alcohol is also broken down differently in saliva and can stay in saliva much longer than even the burped up air. In both of these cases the 2100:1 ratio is also being wrongly applied and falsely raising the BAC reading.
The last two causes for mouth alcohol are solid foods and actual alcohol consumption. When broken down by the body, alcohol can cause the production of acetaldehyde. This chemical is known to also test positive as ethyl alcohol on the handheld PAS devices. Lastly, solid foods, even when tests show there is no alcohol present, can test positive for alcohol. This is mainly because a lot of foods use yeast which is what is also used to make alcohol. Given that solid foods can be stuck in teeth and remain in the mouth longer than liquids, it often causes the test to be inaccurate.
The fail safe on the machine, aside from the observation period which we have already determined is not much of a fail-safe, is the slope test or a slope-detector. Alcohol from the lungs reaches its peak at the end of airflow, whereas mouth alcohol reaches its peak about 1/3 of the way through. Therefore, if the machine detects a decline in the reading, it recognizes mouth alcohol present. However, if there is both mouth alcohol present, and any amount of alcohol in the air from the lung, the slope will be constantly rising and the machine will fail to detect mouth alcohol. Therefore, the "fail-safes" built into the machine are actually rendered useless. PAS or PBT devices rarely, if ever, even have a slope-detector built-in.