First, something I’ve been wondering about that Google hasn’t been too helpful with: Are field breathalyzer tests generally admissible in court? Some cases I’ve read in FindLaw seem to say that they can be if done `correctly’, whatever that means, but there are enough cases challenging this point that I can’t form any opinions on my own.
Now, my main question: Given current testing procedures (possibly not including the aforementioned field breathalyzer tests), what is the minimum BAC we can reliably detect, with reliably' defined as admissible in court’?
(I’m aware that below a certain level, a nonzero BAC is not an indication of intoxication, but let’s say a state wanted its roads to be 100% dry.)
Not a lawyer so this is a WAG. BAC is a measurement and I suppose like all measurements, to have any legal meaning the measuring instrument has to be calibrated according to a procedure that can be shown to be applicable to the intended use. It also must have been calibrated within some period prior to the time of use that can be defended. I.e. records must show that it is highly unlikely to have gone out of calibration within that period. And the calibrating equipment probably needs to be traceable back to a recognized standard instrument as determined by the US Bureau of Standards and Measurements.
Given all of the above I suppose a state that wanted to be absolutely sure could pass a law that anyone testing higher than the error tolerance of the instrument would be in violation of the law.
In most states, you can be prosecuted for a DUI charge with any amount of alcohol or drugs in your system. Any amount that the officer could prove caused “impairment” could result in conviction.
In many states, you are also given an immediate suspension of your driver’s license if your breath test is above .08 BAC. This is a seperate penalty imposed regardless of what the final outcome of the DUI case is. You can appeal this suspension, but it is in front of a DMV representative and not in a court of law.
I am not a lawyer, however plenty of good information is available at this website