What is a Breath Test, and how does it work?

One DWI test that the Police will surely ask you to take is the Breath test or the Intoxilyzer 5000.  This machine “allegedly” can measure the blood alcohol concentration of a person by them blowing air into a testing chamber.  I say “allegedly” because the accuracy and reliability of this machine is a hotly debated issue.

 The Intoxilyzer 5000 works on the theory of Infrared Spectroscopy, which is the absorption of infrared light.  Basically stated, for a given substance, light of specific wavelengths will be absorbed in an amount that is proportional to the concentration of the substance.  Different compounds will absorb different frequencies (wavelengths) of light.  Higher concentrations will absorb more light.

Here is how it is supposed to work, first the person blows into a mouthpiece and when done with sufficient pressure, a pressure switch will close and a tone will sound.  The breath specimen will be accepted by the Intoxilyzer as valid if there was sufficient pressure for five seconds and if the alcohol concentration change was no more than 0.01 per second at the end of the blow.  If not, it is supposed to invalidate the test.  Now to the application of the science, alcohol is supposed to absorb certain wavelengths of light and the machine is supposed to only detect wavelengths of light absorbed by alcohol.  There is a light source at one end of the sample chamber on the Intoxilyzer, and it provides the light that passes through the sample chamber.  The light emanates white light and infrared light.  The light is focused into and out of the sample chamber by lenses, and then passes through a rotating filter wheel at the other end of the chamber.  The filter wheels are designed to filter out potential contaminants of the breath sample.  There must be a filter mechanism because the light that is absorbed is not alcohol specific, and there may be other contaminants in the sample that impact the breath test.  The wheel has a pin hole and three wavelength-specific filters.  The light will then hit a photo detector behind the filter wheel in pulses of white light and the three individual wavelengths.  The photo detector responds to the light hitting it by sending out an electrical pulse with voltage that is proportional to the intensity of the light pulse.  The signals from the three infrared wavelengths are analyzed separately by an electrical processor.  One signal is used for quantitative analysis.  The Intoxilyzer compares the voltage form the photo detector at the end of the specimen delivery with the voltage stored prior to the breath specimen.  The voltage difference is then translated into an alcohol concentration, expressed in grams per 210 liters, by comparing the voltage difference to the voltage differences produced with samples of known alcohol concentrations during the calibration procedure.

The amount of the breath sample actually taken and any reading of whatever alcohol in the sample is very small.  The machine must make a multiplication conversion to an amount great enough for us to understand.  The difference in light emitted and received is run through a computer program in the machine to arrive at a value that can be compared to a 0.08.  The conversion the machine makes on the differences in light would be the equivalent of taking a paper towel tube and increasing its size to that of a 55-gallon drum.  Any error then made by the machine could and would be grossly exaggerated.


Why should I distrust the Intoxilyzer, or why should I hold my breath?

The Intoxilyzer works on the assumption that everyone metabolizes the alcohol they consumed at the same rate and release it through their breath.  Or the assumption is that if you took 2100 centimeters of breath and tested the amount of alcohol in it, the amount of alcohol in the sample would be equal to the amount of alcohol in one milliliter of the person’s blood.  The problem is that almost no one ever meets the assumed characteristics.  One of the assumptions is that the person will have a mouth temperature of 92.8 degrees.  No one will test the person’s temperature before a breath test to see what it is, and a high body temperature or higher mouth temperature will cause the reading to also be higher. Another assumption is that your breath/blood ratio is 2100/1, even the Intoxilyzer Technical Supervisor will state that this is probably incorrect.  Another truth is that your body is not a sealed and heated bottle of alcohol and water perfectly made for the application of Henry’s Law, which is relied upon by the Intoxilyzer.  Henry’s Law basically states that in a solution of water and alcohol, contained in a typical glass container, and kept at a certain temperature.  The alcohol concentration in the gas contained in the space above the solution, will be a predictable value.

The Intoxilyzer Model 5000, comes from its manufacturer without a warranty stating that it is fit for any particular purpose.  The Texas regulations governing the Intoxilyzer Model 5000 do require it to read alcohol accurately.  Well if you consider measuring the reference solution by + or – 0.10 accurate.  The reference solution is contained inside the Intoxilyzer and has a known solution at or near the 0.08 amount, and is used for calibration checks.  The Intoxilyzers used in other states are required to measure the reference solution to within 0.005, unlike Texas, which only requires 0.01.  Want more precision, the Intoxilyzer Model 5000 has a permissible variation of 0.02 from test to test.  What this all means is that if you blow 0.09 on the first test and then blow 0.07 on the second a few minutes later.  That test will be considered valid and you will be considered over the legal limit, and trust me the State will argue that the higher score was more accurate.  But wait there’s more, the Intoxilyzer Model 5000 will almost certainly have prior tests in its database with a no 0.02 agreement.  Furthermore, the Intoxilyzer Model 5000 is not specific for alcohol, meaning other interferents can factor in to its calculations.  Scary when you consider how much is on the line for you.

The Intoxilyzer Model 5000 is made by C.M.I. in Owensboro, Kentucky.  C.M.I. will not disclose the software, programming, or inner workings of the Intoxilyzer to anyone including the Texas Breath Alcohol Testing Program.  Why is it fine for the machine to hide behind a patent, when you cannot even assert your rights of refusal without the State bashing you over the head with it in Court?  The machine also contains a self-checking and self-invalidating process that is known only to C.M.I.  This is interesting because the Intoxilyzer Model 5000 will from time to time invalidate tests for a variety of reasons but will not record what corrective measures or adjustments it made to return it to validating future tests.  It theoretically fixes itself without human intervention.  Throughout science, any testing device such as the Intoxilyzer Model 5000 should be capable of being measured by another alternate technology.  The Intoxilyzer cannot, because of its secret software.  The Intoxilyzer Model 5000 is however contacted periodically by the Technical Supervisor by computer from a remote location to see if it is operating correctly.  The Intoxilyzer Model 5000 reports to the Technical Supervisor whether or not it is working correctly through its self-check mechanism.  Seriously the Technical Supervisor does not actually check it, the machine checks itself and tells the supervisor that it is fine.  Alarmingly, there is no way to validate this because, well, the Intoxilyzer cannot be measured by an alternate technology.  How do you really know if the self-check is operational when you do not even know the programming for the self-check?

 Blood testing is far more accurate and more reliable than the Intoxilyzer Model 5000.  Also the science of Gas-Chromatography, employed in breath testing units in other States, is more accurate and reliable than the science of Infrared Spectroscopy, which is what the Intoxilyzer relies upon.  Another intriguing tidbit is that the Intoxilyzer Model 5000 in Texas does not preserve breath samples for later testing, unlike the Intoxilyzers used in other states.  Which means you lose the ability to have your sample retested with a more reliable technology, for instance gas chromatography, because the State is too cheap to spend a couple of bucks for a sample trap.  Basically the State uses the least reliable instrument, uses it in a way that makes it more likely to make mistakes and does so without affording you the opportunity to prove it wrong without a trial.  Makes you feel all warm and fuzzy about taking that breath test, right?  How about this, you have a right to have a more accurate blood test after you have taken a breath test.  But, in 5 years of criminal law practice, I have never seen or heard of a Police Officer advising a person of this. Why don’t they and why did the State Legislature need to give a person the option for a second test?  Here is the clincher, even if you take the Intoxilyzer test and pass it by being below 0.08, there is still a good chance that you will be charged under the loss of normal use theories spoken of in the above sections, and the State in the trial will most likely object to any admission of the below 0.08 Intoxilyzer results as being irrelevant to the current case.  You are not meant to win, so do not play.     

    

What about the blood test?

             Blood testing is the most accurate form of alcohol testing in Texas, however it is infrequently utilized by Officers.  With that being said, if you have any doubt about whether or not you are above the limit or even close that hesitation should sway you to refuse this test as well.  Once again, if you assert your rights then you will hear about it in Court, but at least the State does not have the evidence to make its case easier.  Like the old saying goes, “It is better to keep your mouth shut and have people think you are a fool, than to open it and prove them right.”

 

Search Warrant 

            You may find this hard to believe but the State will on occasion actually resort to getting a search warrant to get the evidence of intoxication out of you.  Until a few years ago, using the refusal in Court was enough for the State, but now the envelope is being pushed more and more.  In a situation where this is occurring, just be calm and politely refuse.  The State will have to show probable cause to a Judge in order to get the search warrant and then they will have to get a qualified person to then take the sample, which will take some more time thus benefiting you.  There is nothing more for you to do here, but to just remain calm and be nice while refusing.  You will however need to hire an experienced attorney to defend yourself.  

 


After the arrest the Officer told me my license was suspended, what do I do about that?
Administrative License Revocation Hearing (ALR)

            When a person is arrested for DWI and either fails (or refuses to submit to) a breath/blood test, the Police Officer will seize their driver’s license and it will be suspended, unless a timely request is made for an Administrative License Revocation (ALR) hearing.  This is a crucial time to hire a lawyer experienced in the intricacies of DWI and the ALR process, because it is possible to prevent the suspension of the driver’s license.  If successful, the Department of Public Safety (DPS) is obligated to return your driver’s license.

            The Officer most likely would have informed you of the driver license repercussions before the request for a specimen was made.  Here are the possibilities that you will have been warned of, and these apply considering you have had no prior alcohol or drug related contacts during the previous 10 years.  However, if there were prior alcohol/drug contacts within 10 years the suspension period can be up to 2 years.  If you refuse to provide a specimen the license will be suspended for 180 days.  If you provide a specimen and it is over 0.08 you will lose your license for 90 days.  If you are under 21 years of age and have any detectable amount of alcohol in your system you will lose your license for 60 days, but if you are under 21 and provide a specimen which shows you are under 0.08 then the penalties may be less severe.  The Officer will take your license if you fell into the above categories, but you will get a temporary permit that is valid for 40 days.  In order to try and keep your driver’s license, it is imperative that you request an ALR hearing within 15 days of the date the Police Officer informed you that your driver’s license would be suspended.  If you do not and the 15 days expires, your license will be suspended on the 40th day after you received notice from, most likely the Police Officer, or if the Officer did not tell you then from the DPS.  The suspension for failing or refusing a breath or blood test is only automatic if the driver fails to request an ALR hearing.  Now is the time to hire a lawyer. 

If an ALR hearing is requested in a timely fashion, the suspension of your driver’s license will not occur until the ALR hearing is completed, and of course, if the Judge rules to suspend the license.  At the ALR hearing the State must prove by a preponderance of the evidence that:

there was reasonable suspicion to stop or probable cause to arrest the driver;

there was probable cause that the driver was driving or in actual physical control of a motor vehicle in a public place while intoxicated;

the driver was placed under arrest and was offered an opportunity to give a specimen of breath or blood after being notified both orally and in writing of the consequences of either refusing or failing a breath or blood test; and,

the driver refused to give a specimen on request of the officer, OR, that the driver failed a breath or blood test by registering an alcohol concentration of 0.08 or greater per 100ml of blood or 210 liters of breath.

            The ALR hearing is of further benefit because it is here that you can gain discovery of the State’s case.  By issuing a subpoena for the Police Officer, their testimony can be locked down and possibly used to your advantage later on.

            If your driver’s license is in suspended upon completion of the ALR hearing, all hope is not lost.  You may be eligible for an occupational driver’s license.  This will allow you to perform the necessary daily routines such as work, school, and household duties.  You must show good cause for why an occupational driver’s license is needed, but this can be quite broad and encompass many reasons for driving.  The granting of an occupational drivers license requires the filing of a petition and getting an order signed by a judge granting you the right to drive.  This includes a filing fee and various other expenses that the DPS requires, including but not limited to SR-22 insurance and reinstatement and issuance fees.  If granted, an occupational driver’s license will have some restrictions, depending upon your offense.  Typically if you failed or refused a breath/blood test, your driving will be restricted to only 12 hours each day.  If the ALR hearing results in a suspension, it will be a hardship to you in driving, but by not giving evidence against yourself you may win in the end.


Standardized Field Sobriety Tests (or SFST’s)

            There are 3 tests that make up the standardized field sobriety tests and they were developed by the National Highway and Traffic Safety Administration (NHTSA).  During any SFST administration the person’s safety should be considered at all times.  The SFST’s are to be administered and evaluated in a standardized and prescribed manner.  The importance of this cannot be overstated as even NHTSA warns its students during training that:

It is necessary to emphasize this validation applies only when:

  • The tests are administered in the prescribed, standardized manner;
  • The standardized clues are used to access the suspect’s performance;
  • The standardized criteria are employed to interpret that performance

If any of the standardized field sobriety tests elements is changed, the validity is compromised.  (Texas DWI Detection and Standardized Field Sobriety Testing Program—Student Manuel)

 

Horizontal Gaze Nystagmus (HGN)

According to NHTSA, all people have nystagmus, it is just not visible to the naked eye.  Alcohol/depressants, PCP, and inhalants make it visible to the naked eye.  In order to describe what HGN looks like imagine your windshield wipers going across your windshield when it is raining and then imagine the wipers going across the windshield when it is dry.  When HGN is visible in the eyes the eyes will noticeably twitch as they track an object.  The Officer cannot attempt to correlate any Blood Alcohol Content from the HGN test in Court.  The HGN evidence will not be able to be independently verified on videotape so the only person that will typically testify that you had HGN is the Officer that arrested you, and you know he is not wavering from his initial opinion.  Nystagmus can be caused by a number of other causes including head injury, fatigue and some people’s eyes can display nystagmus characteristics naturally. 

There are actually 47 different types of Nystagmus.

Acquired, Anticipatory, Arthrokinetic, Associated, Audiokinetic, Bartel’s, Bruns’, Centripetal, Cervical, Circular/Elliptic/Oblique, Congenital, Convergence, Convergence-Evoked, Dissociated, Downbea, Drug-induced, Epileptic, Flash-induced, Gaze-evoked, Horizontal, Induced, Intermittent vertical, Jerk, Latent/Manifest Latent, Lateral Medullary, Lid, Miner’s, Muscle-paretic, Optokinetic, Optokinetic after-induced, Pendular, Periodic/Aperiodic Alternating, Physiologic, Pursuit after-induced, Pursuit-defect, Rebound, Reflex, See-Saw, Somatosensory, Spontaneous, Stepping around, Torsional, Uniocular, Upbeat, Vertical, Vestibular


HGN Procedure:

During the HGN test the Officer is looking for a total of 6 clues of signs of alcohol impairment.  The Officer looks for these 6 clues during the course of 3 different evaluation techniques, and administers the techniques to both eyes.  The clues are lack of smooth pursuit, distinct nystagmus at maximum deviation, and onset of nystagmus prior to 45 degrees.  The decision point for the Officer on this test is 4 or more clues observed in the eyes.  Decision point refers to the number of clues that would indicate a failure of the test.

The Officer, according to NHTSA guidelines, should ask the person if they have any medical conditions and ask them about the presence of contact lenses, because hard contact lenses may pop out during test.  Also if the person is wearing eyeglasses the Officer should ask that they be removed.  The Officer will position the stimulus, most likely a pen, approximately 12-15 inches from person’s nose and raised slightly above eye level.  The Officer should then check the person’s eyes for the ability to track together.  To do this Officer must move the stimulus across the person’s field of vision.  If the eyes do not track together this could be indicative of a medical disorder, injury, or blindness which would invalidate the HGN test.  The Officer then will check to see if both pupils are equal in size, if they are not this could be indicative of a head injury, which would invalidate the HGN test.

Lack of Smooth Pursuit:

The Officer will start by checking the person’s left eye and move the stimulus out to see if the eye is able to smoothly pursue.  This movement should take approximately 2 seconds to bring the eye from center to side, and then 2 seconds back.  This will then be repeated on the right eye in the same manner.  There should be 2 passes completed for each eye.  The times are requirements from NHTSA and variations will compromise the validity of the test.

Distinct Nystagmus at Maximium Deviation:

Beginning with the left eye, take the eye out to the side until no white is showing.  Hold for approximately 4 seconds.  The Officer should do 2 passes per eye.  Some people exhibit slight jerking of the eye at maximum deviation, even when unimpaired, but when impaired by alcohol, the jerking is said to be very pronounced, and easily observable. (NHTSA Student Manuel)

Onset Prior To 45 Degrees:

Here the officer will most likely use the person’s shoulder as a 45 degree angle indicator.  Starting with left eye, move the stimulus slowly taking approximately 4 seconds to reach the edge of the shoulder.  If the Officer thinks there is jerking should stop, hold stimulus steady, and verify the jerking and its location in relation to the 45 degree angle.

 The questions of key importance are whether the tests:

  •  Were the tests performed correctly per NHTSA guidelines?
  • Were there interferents during the HGN test (traffic, patrol lights, wind, dust, etc…)?  This will interfere with the suspect’s performance on the HGN test, per NHTSA Student Manuel.
  • Was the Officer qualified as an expert on the HGN test, specifically concerning its administration and technique?
  • Was the Officer certified in the administration of the HGN test by the Texas Commission on Law Enforcement Officer Standards and Education?
  • Did the person have a mental or physical condition that would impact the results of the HGN test?

The answers to these questions may have a profound impact on your DWI case and it is imperative that you contact an experienced attorney that can find and exploit the weaknesses in the State’s case. 

Vertical Gaze Nystagmus:

            This is an additional test given by the Officer where he takes the pen up and down as opposed to side to side.  The Vertical Gaze Nystagmus test is not a SFST on par with the HGN test has not been ruled to be admissible as evidence of intoxication in Texas.
Walk and Turn (W&T):

This SFST is a divided attention test employed to test whether or not a person has the ability to concentrate on more than one thing at once, which is theoretically essential to the operation of a motor vehicle.  The W&T is not necessarily valid when administered to subjects over 60 years of age or persons 50 pounds overweight.  The W&T test should be conducted in a reasonably dry, hard, level, and non-slippery surface per NHTSA guidelines.  The Police Officer will give instructions and have the person stand in position where their feet are in a heel-to-toe position, while their hands are to be kept by their sides, and then listen while the Officer informs the person of the test procedures.  The person is to begin the test when informed to do so by the Officer.  The person is to walk heel-to-toe in a straight line for 9 steps while watching and counting out their steps.  When the 9th step is counted the person is to then turn back around by taking a series of small steps.  Then repeat the procedure back.  There are 8 clues that the Officer is looking for, and they are:

  • Loses balance during instruction
  • Starts too soon
  • Stops while walking
  • Misses heel-to-toe by more than ½ inch while walking
  • Steps off the line, or imaginary line. (If done 3 or more times count as “cannot perform test” and give 8 clues)
  • Uses arms for balance (raised 6 inches or more)
  • Turns improperly
  • Takes the wrong number of steps.

The police officer’s decision point is 2 or more clues.  There are a number of problems with this test with one of them being how well could anyone do on this test when an Officer is studying their every move, asking them to take an unfamiliar test, and all the while out on a roadside at night.  Anyone would become nervous to say the least, but in addition to this the Officer does not inform you of the clues that he or she is looking for, nor how many clues they are looking for.  Under these conditions, and taking into account the level of scrutiny involved, this test is simply designed for you to fail.

The questions of key importance are:

  • Did the Officer administer the test correctly? 
  • Did the subject have any injuries or conditions that would have impacted their performance on the tests? 
  • What was the subject’s age and weight?
  • Where were the tests conducted?
  • What were the testing conditions?

The answers to these questions may have a profound impact on your DWI case and it is imperative that you contact an experienced attorney that can find and exploit the weaknesses of the case. 


One Leg Stand (OLS):

The One Leg Stand Test is another divided attention test employed to test whether or not a person has the ability to concentrate on more than one thing at once.  This SFST is not necessarily valid when administered to subjects over 60 years of age or 50 pounds overweight.  The OLS test should be conducted in a reasonably dry, hard, level, and non-slippery surface per NHTSA guidelines.

The OLS begins with an instructional phase where the Officer has the person stand with their feet together with their hands by their sides and listen to the test instructions.  The person is to begin the test only when informed by the Officer to do so.  The person is required to raise one leg, of their choice, for approximately 6 inches above the ground, keeping the toe of the raised leg pointed.  Also while the leg is raised, the person is instructed to watch the raised leg and begin counting out loud to 30 by counting one thousand one, one thousand two and so on.

The Officer is looking for 4 clues on the One Leg Stand Test.  These clues are:

  • Swaying (2 inches or more)
  • Using arms to balance (raising or using arms more than 6 inches)
  • Hopping
  • Putting foot down before 30 seconds.

The decision point for the Officer on the OLS test is two or more clues.  There are a number of problems with the W&T test and the OLS test with one of them being how well could anyone do on this test when an Officer is studying their every move, asking them to take an unfamiliar test, and all the while out on a roadside at night.  Anyone would become nervous to say the least, but in addition to this the Officer does not inform you of the clues that he or she is looking for nor how many clues they are looking for.  Under these conditions and taking into account the level of scrutiny involved, this test is simply designed for you to fail.    

The questions of key importance are:

  • Did the Officer administer the test correctly?
  • Did the subject have any injuries or conditions that would have impacted their performance on the tests?
  • What was the subject’s age and weight?
  • Where were the tests conducted?
  • What were the testing conditions?

The answers to these questions may have a profound impact on your DWI case and it is imperative that you contact an experienced attorney that can find and exploit the weaknesses of the case.

Other known factors that may impact SFST performance:

Nervousness, fear, fatigue, illness, traffic, wind, dust in your eyes, head lights, police car strobe lights, weather conditions, back problems, leg/knee injuries, ankle/foot problems, inner ear disorders, conditions at the testing site, weight, age, footwear, lack of coordination