What factors can contribute to faulty breath test results?

Improper calibration, mouth alcohol, and certain medical conditions are critical factors that can significantly affect the accuracy of breath test results. Breathalyzers require precise calibration to ensure that they can accurately measure blood alcohol content (BAC). If the device is not properly calibrated, it may give false readings, leading to incorrect assessments of a driver's intoxication level.

Mouth alcohol can also interfere with the test results. If an individual has residual alcohol in their mouth—potentially from recent drinking or use of certain mouthwashes—it can lead to a higher reading than what is actually present in the bloodstream. This is because the breathalyzer might detect the alcohol vapor emanating from the mouth rather than what is absorbed into the bloodstream, resulting in misleading BAC figures.

Certain medical conditions can also impact breath tests. For example, conditions that influence metabolism or that cause the body to produce substances similar to alcohol can complicate the results. Such variables highlight the importance of careful procedural adherence and consideration of individual circumstances during DUI investigations to ensure fair and accurate outcomes.