Whenever a motorist accused of driving while intoxicated agrees to submit to a breath test, the state's star witness at trial will be the technical supervisor, the state's expert on the breath test machine. One of the highlights of the state's expert's testimony is the calculation of your client's alcohol concentration at the time of driving and the number of drinks it took to get to that point. This pseudo-scientific theory is called retrograde extrapolation.
While the prosecutor is asking the technical supervisor to determine these numbers for the jury, the technical supervisor will be sitting at the witness stand furiously punching numbers into a calculator. The testimony all seems