The district attorney in your Pennsylvania DUI case will call several witnesses, including the police officer who arrested you and an "expert," usually a technician from the crime lab who analyzed your chemical test to determine your blood alcohol content (BAC). A skilled Pennsylvania DUI attorney from Zachary B. Cooper, Attorney at Law, P.C. will call an independent expert to the stand to demonstrate that there is more than one way to interpret your chemical test result.
Testimony from an independent expert is an important part of an effective Pennsylvania DUI or driving under the influence of drugs (DUID) defense. The defense expert's primary job is to testify about any possible alternative explanations to the district attorney's charge that you were driving under the influence. A strong defense expert will supply knowledgeable testimony about the scientific aspects of intoxication and challenge the district attorney's expert's conclusions.
Your Pennsylvania DUI attorney will ask the defense expert open-ended questions that permit the expert to testify freely on your behalf. Choosing the right defense expert in your Pennsylvania DUI case is crucial - you need an expert who thoroughly understands the science of intoxication and can explain issues to jurors in a way they can understand and appreciate. In some cases defense experts were former prosecution witnesses, which gives them even greater credibility with jurors.
An effective defense expert will challenge the district attorney's allegation that you were driving under the influence. One of the most crucial concepts the defense expert can testify about is rising BAC. The jurors may be unaware that a driver's BAC can continue to increase after the last drink is taken.
Chemical tests administered in Pennsylvania DUI cases are usually given sometime after you were driving. Because your BAC may have continued to rise, you may have been over the legal limit at the time your chemical test was administered, but not when you were driving.
The only relevant figure is your BAC within two hours of driving, and that may be difficult to pinpoint several hours after you were last behind the wheel. The district attorney's expert will testify that your BAC exceeded the legal limit while you were driving, and it's the defense expert's job to contradict that testimony.
A strong defense expert will also testify about possible inaccuracy in breath and blood tests. For example, the defense expert can explain to jurors how an improperly calibrated breath-testing machine might give an inflated reading, or how an incorrectly stored blood sample might ferment and actually create alcohol, increasing your BAC result.
An effective defense expert might also provide input on your field sobriety test performance and point out aspects of the test that show you were not or may not have been impaired.
A Pennsylvania DUI charge focuses on mental and physical impairment, and a strong defense expert can help jurors understand that when a person drinks alcohol, mental impairment always occurs before physical impairment takes place. Physical impairment can be masked by individuals with a high tolerance for alcohol, but mental impairment cannot be disguised.
If you didn't show any signs of mental impairment, then any physical problems you displayed must have been caused by factors other than alcohol intoxication. The expert can testify about many conditions that might cause physical impairment, including injury, illness, disability or fatigue.
Once your Pennsylvania DUI attorney has finished examining the defense expert, the district attorney can begin cross-examination. The district attorney will likely employ the same tactic your Pennsylvania DUI lawyer used when questioning prosecution witnesses - asking the defense expert "leading" questions that require only a yes or no response. However, a well-prepared and experienced defense expert will make an effort to defuse this strategy.
Your Pennsylvania DUI attorney will meet with the defense expert before your trial to review the expert's opinions in your driving under the influence case. They will strategize ways to overcome any weaknesses in your case and try to anticipate any attacks from the district attorney.
Having a respected expert on your defense team may provide you with a significant advantage in your Pennsylvania DUI case. An experienced Pennsylvania DUI lawyer from Zachary B. Cooper, Attorney at Law, P.C. will thoroughly review your case and determine how a qualified defense expert might contribute to your driving under the influence defense strategy.