In our last post, we mentioned several important factors that need to be considered when scrutinizing the reliability of alcohol tests in drunken driving cases. As we mentioned, the scientific acceptability of breath testing software; proper calibration, use and maintenance of breath testing devices; proper performance of blood testing and chain of custody issues should all be scrutinized with breath and blood test results.
Whenever prosecutors rely on alcohol testing to build a DUI case, there are also biological factors that should be considered. These include: whether the defendant’s blood alcohol level may have been higher due to the issue of timing; whether the testing device may have been thrown off by other substances in the defendant’s system at the time of testing; and whether the defendant’s body temperature or lung capacity may have thrown off the readings.
Other issues need to be considered when prosecutors build a drunken driving case based on a second statutory basis for drunken driving charges. Pennsylvania's drunken driving specifies that an individual can also be charged with DUI when they have drank enough alcohol so as to render themselves unable to safely drive, operate or be in actual physician control of the movement of a vehicle.
This second legal basis for drunken driving charges is based on the inability to safety drive, and prosecutors make use of a variety of types of evidence to prove this point. They look, for instance, at the driver’s operation of the vehicle, specifically whether there were any moving violations. They look also at the driver’s appearance, smell, and demeanor upon being pulled over.
In our next post, we’ll look at some of the other pieces of evidence prosecutors rely on to build drunken driving cases on this second legal basis, and the of the legal issues that an experienced criminal defense attorney will scrutinize in building a strong defense case.