If you're facing a Pennsylvania DUI charge, the district attorney must prove every element of the offense against you in order to obtain a conviction. The elements of the offense of a Pennsylvania DUI are driving a vehicle under the influence, or violating the state's "per se" laws, which means having a blood-alcohol content (BAC) of .08 percent or greater.
If you took a breath test or blood test when you were arrested for Pennsylvania DUI, the results of that test will be a key piece of evidence in the district attorney's case against you. However, this evidence may be subject to challenge. Your Pennsylvania DUI attorney at Zachary B. Cooper, Attorney at Law, P.C. will thoroughly analyze all of the evidence in your drunk driving case to determine whether it can be challenged.
Also, chemical tests are sometimes administered hours after a suspected Pennsylvania DUI driver was last behind the wheel, and may not accurately reflect the BAC at the time of driving.
The chemical tests used to determine BAC are sometimes prone to error. Preliminary alcohol screening, or PAS tests, are among the least reliable chemical tests used in drunk driving cases. These handheld breath-testing devices don't detect mouth alcohol, which can spike your BAC reading. The presence of mouth alcohol is especially common if you had a drink within a certain time before being tested.
The breath-testing machines used in police stations in Pennsylvania DUI investigations can also be fraught with problems. Breath testing machines don't take the temperature of your breath, even though elevated breath temperature can artificially increase your BAC result.
All breath testing machines are designed to test an "average" person that doesn't really exist, as both men and women have varying metabolisms, body types, weight, and other variables. All of these factors affect alcohol metabolism.
Blood test results can also be problematic. A blood sample's integrity can be compromised. For example, the protocol for a blood test in a Pennsylvania DUI investigation requires that the blood be drawn into a tube with a precise mixture of preservative and anti-coagulant at the bottom. However, the powder mixture in the bottom of the tube is never checked for accuracy. There may also have been a lengthy delay before your blood sample was tested, which may have opened the door for an error to occur.
Because errors sometimes occur in chemical testing, a blood or breath test that showed a BAC of .08 percent or greater may be subject to challenge. There are many effective challenges to the evidence in a per se drunk driving case. Your Pennsylvania DUI lawyer at Zachary B. Cooper, Attorney at Law, P.C. will analyze the evidence in your drunk driving case to determine whether it's open to challenge.