Breath tests are the most common piece of evidence submitted in DUI cases, but there are many factors that can actually make them unreliable and insufficient evidence. In some cases, law enforcement officials have even acknowledged the invalidity of breath test results while still using and submitting them as evidence. If you face DUI charges on the basis of a breath test, these five factors may be relevant.
1. Health issues
There are plenty of different health issues that can have an impact on the results of a breath test and cause it to result in a false positive. Some of the most common culprits of this problem include diabetes, hypoglycemia and auto-brewery syndrome. Other issues, such as seizures, poor vision, vertigo and mobility challenges, can influence field sobriety tests as well.
2. Electronic interference
Some breath test devices rely on radio frequencies to produce a result. More advanced models may display an error code when interference is detected, but other types may have results impacted by the interference. Electronics such as police radios, cell phones and walkie talkies all have the potential to impact the reading of a breath test.
If your breath test is administered in an area where there is dirt, or if you become ill and vomit, it could be easy for the device to become contaminated and produce an unreliable result. Blood and moisture are potential contaminants, too, and if a law enforcement officer is not careful, any of these can have an undue effect on the reading produced by the breath test.
4. Exposure to certain materials
If you have eaten or inhaled certain materials before a breath test is administered, traces of those materials can trigger a false positive. Some paints and paint thinners, for example, produce fumes that mimic the effects of intoxication in a person's body. Similarly, eating some types of bread, like rye, can inflate the recorded BAC.
5. Device malfunction
Perhaps one of the most common yet overlooked causes of unreliable breath tests is simple device malfunction. Like any other piece of technology, a breath test device is far from infallible, and the machinery it relies on can become damaged or otherwise faulty. In such cases, the rendered result is unreliable.
There are many reasons why a breath test may be disputed, and if you have a DUI charge, your test may be disputable, too. Contacting a local and reputable attorney can help you better understand your legal rights and what the next step in your case is.