DUI cases involve scientific evidence gathered for law enforcement purposes. (This is also known as forensic scientific evidence.) The scientific evidence used in DUI cases is used primarily to determine the driver’s blood alcohol level. This is done a number of ways:
-Direct measurement of the blood for alcohol content
-Breath Measurements that detect alcohol exhaled through the driver’s lungs
-Field sobriety tests (of limited scientific validity)
When it comes to the breath testing, there are two tests that are conducted: a PAS test and an evidential test. The PAS test (PAS stands for “Preliminary Alcohol Screening”) test is less accurate than the more commonly known “breathalyzer” that is in fact an breath alcohol measuring machine called an “evidential” test (because of its higher accuracy and use as evidence in DUI cases.)
Sometimes the prosecution (or the DMV) will want to use the PAS test results to show the driver’s blood alcohol level was above 0.08 at the time of driving. Other times, the driver will want to introduce the evidence because it might tend to show the driver was below 0.08 % at the time of driving.
PAS Admissibility Requirements:
For use at the DMV or in a criminal court setting, a party seeking to admit PAS results has to show one of two things:
-Title 17 compliance, or
Title 17 of the California Code of Regulations is a complex set of standards and rules used for forensic evidence gathering. To meet Title 17 requirements, the accuracy of the equipment used, the maintenance of the equipment, the training of the operators and the proper use of testing equipment all have to be met.
Where strict compliance of Title 17 regulations cannot be shown, a party seeking to admit PAS evidence can still use the evidence if it’s “scientific validity” can be shown. Two cases in California explored this concept: People v. Adams and Coniglio v. DMV.
To establish scientific validity of a PAS machine’s results, the party seeking to introduce the evidence has to show:
1. the particular apparatus utilized was in proper working order
2. the test used was properly administered, and
3. the operator was competent and qualified.