Results confirm the hypothesis that there is a typical distribution of blood alcohol contents (BAC's), and that this distribution has a significant population density for BAC's all the way down to zero. This ordinary distribution can be used as a standard against which to evaluate the performance of particular precincts, machines, and operators. Application of these findings shows that the classic breathalyzer model 900/900A not only can be manipulated, but there is good evidence that in at least one precinct that such manipulation occurred. The existence of such manipulated data confirms the suspicion that an overzealous prosecutorial urge may lead to the misuse of an otherwise functional instrument. Results suggest that all police who use evidentiary breath testing (EBT) keep a running log of readings to preserve evidence of proper or improper use of EBT. In addition, the switch to double-blind instruments should be accelerated to prevent manipulation; and the 900/900A machines should be decertified for use as EBT's. 3 tables and 4 figures. (Author abstract modified)