Mouth alcohol can be caused in many ways. Belching, burping, hiccupping or vomiting within 20 minutes before taking the test can bring vapor from alcoholic beverages still in the stomach up into the mouth and throat. Dental bridges and dental caps can trap alcohol. Potential defenses in a given drunk driving case are almost limitless due to the complexities of the offense. This may be difficult if, as in the case of accidents, there are no witnesses to his being the driver of the vehicle.
Sobriety roadblocks present particularly complex issues.
Incriminating statements may be suppressed if warnings were not given at the appropriate time. Too, witnesses can testify that you appeared to be sober. There exists a wide range of potential problems with blood, breath or urine testing. Radio frequency interference can result in inaccurate readings. Again, a number of complex physiological problems are involved here.