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Can DUI Breath Test Results Be Challenged?

If you did submit to a State administered breath test, in light of your presumption of innocence, the prosecution must prove that at the time of your test the electronic equipment was in proper working order, that it had been properly maintained, and that the breath test was conducted in a proper fashion.

This is an area of DUI-DWI law that is a hotbed of appellate litigation on both the federal and state level.

If the prosecution fails to provide all of this proof, the test results may be excluded (not allowed) as part of the trial evidence against you. In most states however, discrepancies in the manner that the breath test operator conducted the test may go only to the weight of the State’s chemical test evidence. This means that the test result comes into evidence and then your attorney puts up evidence to counter it.

For example, you may have excellent proof that your breath test was taken during the absorptive stage of alcohol intake and metabolism (burn off), and this can cause falsely high readings. If these test results are barred from being used against you, it is likely the DUI-DWI charges against you may be dismissed, or a “reduced” charge (to a less serious offense than drunk driving) may be negotiated by your attorney.

If this is not possible, then at least your chances for acquittal are improved because you can show flawed evidence (by use of expert testimony) at trial. Another possibility is that the State’s representatives simply cheated at reporting breath test accuracy reports.

Inaccurate breath test results due to a faulty breath machine or operator error is one of the best ways to win DUI cases. We will file a motion to suppress this evidence way before your case ever goes to trial.

Challenging DUI Breath Test Results in Court

A thorough DUI attorney will find answers to the following exhaustive list of questions as he or she builds your drunk driving defense, and then advise you how to beat a DUI breath test. If your blood alcohol content (BAC) results from a breath test can be excluded from the evidence, your chances at a favorable outcome are strengthened.
A. Whether the method of testing used is scientifically accurate and reliable.

1. What type of breath testing instrument was used to test the defendant’s breath?

2. Has this instrument been approved either statutorily or administratively in this state? If so –

a. By whom was it approved?

b. When was the instrument most recently approved?

d. Has the instrument been altered in any way by the manufacturer or by the user since it was last approved?

3. Has this make and model testing instrument been the subject of a product recall or class action litigation based upon any type of malfunction?

4. If the instrument has been factory serviced recently, was the machine checked for calibration accuracy after being shipped back from the factory?

B. Whether the testing equipment used was in proper working order when the test was administered to the defendant.

1. Is certification by a state agency or officer required for any of the breath testing equipment used in this case? If so –

a. By whom is the certification given?

b. What type of certification is required?

c. What are the certification standards?

d. How often is certification required?

e. When was the equipment used in this case most recently certified?

f. Has any part or component of the breath testing instrument (including its computer software) been changed or modified since the most recent certification?

g. In what manner was the equipment used in this case certified and who certified it?

h. If the testing device was also inspected to determine its capability to detect and report interfering substances, give full details on how, when and by what method such verification was conducted.

2. Is periodic inspection or testing of breath testing equipment required in
this state? If so –

a. What agency or officer conducts the inspections or tests?

b. How often must the inspections or tests be conducted?

c. When was the equipment used in this case last inspected or tested?

d. What is the name of the person who conducted the last inspection or test on the equipment used in this case?

e. What training and other qualifications are required of persons who conduct such inspections or tests?

f. Did the person who last inspected or tested the equipment used in this case possess the required qualifications?

g. Is certification required of persons who conduct such inspections or tests? If so –

By whom is the certification issued?

How often is certification required?

What are the certification standards?

Was the person who last inspected or tested the equipment used in this case properly certified at the time?

h. What components of the breath testing equipment must be inspected or tested?

i. What are the published inspection or testing standards?

j. What were the results of the last inspection or test conducted on the breath testing instrument and the breath-alcohol simulator used in this case?

k. In what manner may proof of compliance with the inspection or testing requirements be entered into evidence at trial?

l. Did the certifying officer or technician strictly comply with the required testing protocol for the breath machine as published by the state?

3. If a periodic inspection or testing of breath testing equipment by a state agency or officer is not required, what are the testing or inspection requirements for such equipment?

a. Who is responsible for conducting the periodic inspections or tests?

b. What are the inspection or testing standards?

c. Was the testing equipment properly and timely inspected prior to its use for forensic analysis in this case?

4. What periodic maintenance procedures, if any, are required to be performed on the breath testing equipment used in this case?

a. Were the maintenance procedures properly and timely performed by qualified persons prior to the use of the testing equipment in this case?

b. Were all calibration check test cards provided to verify that the breath device was properly checked?

C. Whether the breath testing equipment was properly operated by a qualified person.

1. Have uniform or official procedures for the operation of the breath testing equipment used in this case been adopted? If so –

a. What are the procedures?

b. In what form have such procedures been implemented (checklist, operating instructions, etc.)?

c. What forms, lists, or other documents must operators of the testing equipment complete when administering a breath test?

d. Were the checklists or operating instructions followed by the operator in this case?

e. Were the required forms or documents contemporaneously completed by the operator?

f. What is the required length of the period of waiting (deprivation) and observation prior to the taking of a breath sample?

g. How long was the defendant observed prior to the taking of a breath sample in this case?

h. Who observed the defendant and in what manner was the observation performed?

2. Is certification or other proof of qualification required of operators of breath testing equipment? If so –

a. What are the training and educational requirements to be qualified to be a breath test operator?

b. What type of certificate or permit is required?

c. By whom is the certificate or permit issued?

d. How often must the certificate or permit be renewed?

e. Had the operator of the breath testing equipment in this case been timely issued a certificate or permit at the time of testing in this case?

f. Had the operator received the required amount of training?

g. In what manner may the qualifications of the operator be established in court?
D. Whether the breath test was administered within the required period.

1. Is there a statutorily or administratively required period within which a breath test must be administered? If so –

a. Upon what event does the time for the required period begin to run?

b. What is the length of the period within which the test must be administered?

c. Was the test administered to the defendant within the required period in this case?

d. What is the penalty for not administering the test within the required period?

2. Whether or not there is a statutorily or administratively required period for administering a breath test, was the test administered to the defendant within a reasonable period after the end of driving?
CHECKLIST FOR DETECTION OF SCIENTIFIC ERROR IN BREATH TESTING
A. The defense of a lower partition ratio.

1. Determining the defendant’s temperature at the time of testing.

a. Was the defendant’s temperature taken at or near the time of testing?

If so, what was the temperature and who took it?

b. If the defendant’s temperature was not taken at or near the time of testing –

Was the defendant suffering from injury, illness or disease at the time of testing?

Had the defendant been exposed to excessive heat or trauma prior to the time of testing?

Had the defendant taken psychotropic drugs prior to the time of testing?

Did other factors exist that may have caused the defendant to have had an elevated body tem¬perature at the time of testing?

Did the defendant receive any medical care or treatment after being incarcerated that may yield a test of body temperature?

c. From the above conditions and factors, what was the defendant’s actual or estimated body tem¬perature at the time of testing?

2. Determining the hematocrit of the defendant’s blood at the time of testing.

a. Has a sample of the defendant’s blood been tested for
hematocrit?

If so, on what date was it tested and what did the test indicate?

What was the estimated hematocrit of the defendant’s blood at the time of the breath test?

3. Using the defendant’s actual or estimated body temperature at the time of the breath test and/or the estimated hematocrit of the defendant’s blood at the time of the breath test, what was the defendant’s estimated partition ratio at the time of the breath test?

B. The defense of testing during absorption and the rising BAC defense [likely applicable to all traditional (common law) cases and to the per se count in some states].

1. At what time did the defendant commence drinking on the occasion in question?

2. At what time did the defendant cease drinking on the occasion in question?

3. How much alcohol did the defendant consume?

4. Did the defendant consume any food during the course of drinking or within an hour prior to the commencement of drinking? If so –

a. What type of food was consumed?

b. How much food was consumed?

c. When was the food consumed?

5. At what time did the alleged offense occur (i.e., when did the driving episode END)?

6. At what time was the breath or blood test administered to the defendant?

7. Did the defendant consume or take any medication or drugs prior to or during the period of drinking? If so –

a. What medications or drugs were consumed or taken?

b. When were the medications or drugs consumed or taken?

8. Was the defendant suffering from disease or illness at the time of drinking? If so –

a. Describe the disease or illness.

b. When did the disease or illness begin?

9. Was the defendant subjected to stress at the time of drinking? If so –

a. What was the cause of the stress?

b. When did the stress begin?

10. Did the defendant engage in strenuous physical exercise during or after the period of drinking? If so –

a. Describe the exercise.

b. For how long a period was the defendant engaged in the
exercise?

11. Based on the above facts, was the defendant in the absorptive phase of the alcohol distribution pro¬cess when the breath test was administered?

12. Was the defendant involved in an accident wherein gastric emptying may have been stopped or slowed due to trauma?

a. Was any hospital test of blood alcohol taken as a part of the treatment?

b. If a hospital blood test was taken, what time was this blood drawn?

13. Based on the above facts, was the defendant in the absorptive phase of the alcohol distribution pro¬cess at the time of the alleged offense?

14. Based on the above facts, did the defendant’s BAC rise between the time of the offense and the time of testing?
C. Defenses related to the integrity of the breath sample.

1. Whether the breath sample was contaminated by regurgitated contents or gas from the stomach or the esophagus or due to mouth cavity alcohol being trapped.

a. Did the defendant have any pockets (e.g., from wisdom tooth extraction), tooth cavities or broken fillings at the time of testing?

b. Was the defendant wearing dentures at the time of testing?
If so –

Were the dentures upper or lower dentures?

Was the testing officer aware of the dentures?

c. Was denture adhesive used to secure the denture plate(s)? If so, what type and brand of denture adhesive was used?

d. Was the testing officer aware of the presence of dentures or dental plates?

e. If asked by any officer, what did the defendant report as to the time of his or her last drink prior to breath testing?

f. Was the defendant ever permitted to rinse his or her mouth prior to submitting to breath testing?

g. Did the defendant either hold his or her breath or engage in hyperventilation just prior to testing?

h. Was the defendant crying at the time of or during delivery of the breath sample?

2. What was the composition of any denture or plate material?

a. Was the material hard and inflexible or pliable and flexible?

b. Can a sample of the material be tested to see if it retains or absorbs alcoholic beverages?

3. Did the defendant have any active tooth, gum or mouth pain that was being treated with any type of topical medication? If so

a. What type and brand of topical pain ointment, dental packing, dental plug or salve was used?

b. Does the container indicate any alcohol being part of the contents of the pain relief medicine?

c. Are there any other chemicals in the pain relief medication of similar composition or chemical make-up to ethanol?

4. Whether the breath sample was contaminated by stomach alcohol.

a. For how long a period was the defendant observed by the testing officer prior to the taking of the breath sample?

b. Did the defendant burp, belch, hiccup, vomit or otherwise regurgitate any stomach contents or stomach gases during the period of wait¬ing and observation? If so –

What type of regurgitation activity occurred?

How many times did it occur during this period?

Was the testing officer aware of the regurgitation activity?

If noticed by the testing officer, was a new observation period begun, as required by state law?

Was the defendant’s mouth open or closed during the regurgitation activity?

How long before the taking of the breath sample did the regurgitation activity occur?

5. Whether the breath sample was contaminated by non-consumed alcohol.

a. Did the defendant use or consume breath mints, cough drops, lip ointment, breath fresheners, cola drinks or other substances that may have contained alcohol or similar compounds within an hour prior to the administration of the breath test?

b. If so, what was used or consumed and in what amounts?
6. Whether the breath sample was contaminated by acetone or other endogenous substances.

a. Is the defendant a heavy smoker, an alcoholic, or a diabetic?

b. Had the defendant been adhering to a “high protein” or on a low carbohydrate diet at the time of testing?

7. Whether the breath sample was contaminated by inhaled substances.

a. Was the defendant exposed to organic or alcoholic fumes during the 24-hour period prior to testing? If so –

b. To what type of fumes was the defendant exposed?

c. For how long a period was the defendant exposed?

d. How long prior to testing did the exposure end?

e. What was the degree of the defendant’s physical activity during the exposure?

f. Did the defendant use a functioning respirator or filtration mask while being exposed to the vapor?

8. Whether the integrity of the breath sample was compromised by the presence of an elevated body temperature.

a. What was the defendant’s body temperature at the time of testing? (See item A.1 above)

b. Did the defendant ever verbally complain of being “too hot” or overheating.

D. The defense of simulator test error.

1. Was the breath testing instrument used in this case tested on a wet-bath breath-alcohol simulator? If so –

a. When was the wet-bath simulator test performed?

b. Who performed the simulator test?

c. What were the results of the simulator test?

d. Who prepared the alcohol-water solution used in the simulator?

e. When was the alcohol-water solution prepared?

f. What was the concentration of alcohol in the solution?

g. How and where was the alcohol-water solution stored after preparation and before the vapor was ported into the simulator?

h. When was the concentration of alcohol in the solution last checked and who checked it?

i. When was the solution that was in the simulator at the time of the simulator test inserted into the simulator and how many simulator tests had been run since it was inserted?

j. When a simulator test is run, how is the vapor replaced in the simulator?

k. At what temperature was the simulator test run?

l. When was the simulator last checked for the presence of leakage from seals and was leakage found to exist?

m. What qualifications are required of simulator test operators?

n. Did the simulator test operator in this case possess such qualifications?

o. In what manner may the results of a simulator test be introduced into evidence?

p. Was the simulator solution used in testing the breath testing instrument used in this case pre¬served or destroyed?

q. If preserved, where is it located?

r. When and how was the thermometer in the wet-bath simulator checked for accuracy at being the state-approved mandatory temperature?

E. The defense of faulty dry gas simulator.

1. Was the dry gas simulator purchased from a certified supplier that verifies the contents of its canisters?

2. Did someone at the state verify the contents of the dry gas mixture?

3. Was the dry gas canister kept at a proper temperature and rotated to assure full mixture of the gases?

F. The defense of radio frequency interference.

1. What type and model of breath testing instrument was used in this case?

a. Has this type of instrument been found by the National Highway Traffic Safety Administration, by its manufacturer, or by any independent testing agency or institution, to be susceptible to radio frequency interference?

b. Does this instrument have a history locally, of being affected by radio frequency interference?

c. Did the incident involving radio or cell phone communication in the room containing the breath machine occur while the defendant’s testing was being conducted?

2. Had the breath testing instrument used in this case been tested for susceptibility to radio frequency interference? If so –

a. By whom was it tested?

b. When was the test performed?

c. What type of test was performed?

d. What were the results of the test?

e. Were such tests provided by or recommended by the manufacturer of the instrument?

3. Had the breath testing instrument used in this case been modified to render it less susceptible to radio frequency interference? If so –

a. What modifications were made?

b. When were the modifications made?

c. By whom were the modifications made?

d. Were such modifications provided by or recommended by the manufacturer of the instrument?

4. If the instrument has not been modified to render it less susceptible to radio frequency interference, have such modifications been recommended by the manufacturer of the instrument?

5. Was a police radio in operation within 150 feet of the breath testing instrument at the time of the administration of the defendant’s breath test? If so –

a. Where was the radio located?

b. At what frequency was the radio being operated?

c. What was the name of the person (or a description of the person) who was operating the radio?

6. Was the breath testing instrument used in this case equipped with a radio frequency interference detector? If so, was the detector connected and in full operating condition?

7. Do administrative rules or regulations exist that deal with prevention of possible radio frequency interference in breath testing instruments?

a. If so, were such rules or regulations complied with in this case?

b. What steps, if any, did the breath test operator take to confirm that all electronic devices had been turned off prior to breath testing?

G. Defenses related to the preservation of a sample of the defendant’s breath.

1. Are the police required to preserve a sample of the defendant’s breath?

2. Was a sample of the defendant’s breath preserved in this case? If so –

a. Where is the sample located?

b. For how long a period must the sample be preserved by the police?

c. For how long a period will the sample be suitable for chemical testing?

3. If a sample of the defendant’s breath was not preserved, was replicate testing performed?

a. If so, what were the results of each test?

b. If not, is replicate testing required in this state or jurisdiction?

H. Replicate tests being correlated.

1. Did the breath test operator obtain two sequential inhalations of breath that were within numerical agreement to within +/- 0.020?

2. Did one inhalation report as a numerical value and the other report as being insufficient (or similar designation of the delivered sample being deficient)? If so

a. Did the breath test operator offer a new opportunity to re-test and provide two sequential samples?

b. In the event of physical inability to deliver a replicate test, did the breath test operator offer an alternative method of testing (e.g., blood testing) which requires no physical ability to deliver a long, continuous, fixed exhalation?

Further Reading

If you’d like to learn more about DUI breath tests and DUI breath test machines, take a look at some of our other in-depth articles on the subject below: