Improper observation period – officer is required to continuously observe the test subject for twenty minutes prior to administering the test.
Any burp, belch or regurgitation could result in inaccurate breath results due to the fact that stomach contents will generally have higher concentrations of alcohol than breath alone.
Before a second attempt after you have belched, burped or vomited, the officer should allow you to rinse your mouth and then conduct another twenty minute observation period.
Certain medical, dental, or respiratory conditions may make any test result unreliable.
Your general condition and demeanor is inconsistent with the test results.
Electrical or radio frequency interference can influence a breath test machine to give artificially high readings. Other situations, such as smoking or shared power supplies, may also affect results.
Your exposure to certain environmental conditions could affect the results of the test. Exposure to certain products such as lacquer, gasoline, or paint, has cumulative effects, potentially causing false positive readings.
If an accident has occurred and your airbag deployed, it could cause certain circumstances which could lead to alterations to the test results.
Videotape could show that your ability to drive is inconsistent with an extremely high test result, supporting your sobriety.
Unanticipated alcohol sources such as Nyquil, lip balms, and toothache medication.
Oral contaminants that contain alcohol such as breath mints or smokeless tobacco.
Police failing to notify you that you have the right to an independent chemical test.
Officer administering the breath test was not properly trained or certified.
Police failed to follow the N.H.T.S.A. manual when administering test.
Failing to properly maintain and/or calibrate the breath test machine.
Reverse extrapolation showing that an increasing BAC at the time of testing supports a lower BAC at the time of operation.
Precision of breath test machine has margin of error.
Proof that alcohol was consumed AFTER you had operated your vehicle, thus not providing an accurate test representing your BAC at the time of operation.
A high tier test result from a urine test can be attacked by showing you had not urinated for 3 or more hours, thus resulting in inaccurate BAC levels at the time of operation.
The collection of urine sample was not properly witnessed.
The urine sample was placed in a compromised container leading to the introduction of potential contaminants.
Not properly sealing or labeling the urine sample container.
Failing to properly refrigerate urine sample.
Using unproven techniques or methods when analyzing urine sample.
Blood sample taken outside of three hour time period.
Blood sample was taken involuntarily or was unconstitutionally coerced from suspect.
Blood sample was not properly retained or kept in the proper chain of custody.
Inadequate training of technicians taking the blood sample.