Examination of Defense Criminalist

In a California DUI / DWI criminal trial, the prosecutor will call numerous witnesses, including the arresting officer and a prosecution "expert." This expert is usually an employee of the sheriff's department who will interpret the defendant's chemical test results, blood alcohol content (BAC), and field sobriety tests. A skilled drunk driving attorney from The Kavinoky Law Firm will call an independent defense expert to show that the driver's chemical tests can be interpreted in an entirely different way.

The use of a qualified defense expert is of the utmost importance in drunk driving or driving under the influence of drugs (DUID) cases. Experts can discuss a multitude of subject, but their primary purpose in a drunk driving defense is to support the notion that there are other possible explanations for the prosecution's evidence that the defendant was driving under the influence. Skilled defense experts testify about the scientific aspects of alcohol intoxication, and can knowledgeably rebut the prosecution expert's theories and conclusions.

Direct examination of the defense's expert is very similar to the direct examination of other witnesses. The DUI / DWI defense lawyer will ask the expert open-ended questions so that he or she can testify freely. The selection of the expert is critical to the success of this aspect of the defense. The expert should be knowledgeable in his or her field and able to explain technical and scientific information in a way the jury can understand and appreciate. Some defense experts were once prosecution toxicologists, which is a big help to the defense because the jury sees that the crimnalist has chosen to work on behalf of defendants.

Defense experts can sometimes produce studies and resources that the prosecution can't access. Defense experts also help with the defense of DUI / DWI cases by preparing the defense attorney in his or her cross-examination of the prosecution's criminalist.

A skilled defense expert will aggressively challenge many prosecution claims. One of the most import idea the expert can explain to the jury is the concept of rising blood alcohol content (BAC). Jurors are typically unaware that a driver's BAC can continue to rise even after he or she quits drinking.

Since chemical tests are always administered after the motorist was behind the wheel, sometimes even an hour or two after driving, the driver's BAC could easily be .08 percent at the police station, but that's not illegal.

In a driving under the influence case, the only thing that matters is the motorist's BAC at the time of driving, and that's very hard to pinpoint using a test taken several hours later. The prosecution's expert will testify that the driver must have been over the legal limit the entire time, and it's up to the defense expert to refute that testimony.

A defense expert can also explain the inherent flaws in both breath and blood tests, such as what happens when fermentation takes place in an improperly stored blood sample, or how BAC readings can be inflated when breath machines are not properly calibrated.

A skilled defense expert will also use a driver's performance on field sobriety tests to demonstrate that the accused driver was not under the influence while behind the wheel. The expert will use aspects of the driver's performance on the test to show that he or she displayed no mental or physical impairment.

Mental and physical impairment is at the heart of every California DUI / DWI case. A knowledgeable expert will testify that mental impairment always occurs before physical impairment when a person is under the influence of alcohol. If there is no evidence of mental impairment, then any poor physical performance must have been caused by something other than intoxication. The expert will explain that there are many conditions that can cause physical impairment, including injury, illness, or fatigue.

Once the defense attorney has finished examining the expert, the prosecutor begins cross-examination. Just as the defense attorney does during cross-examination, the prosecutor will likely ask leading questions that are designed to draw only yes or no answers. Because this is the prosecution's opportunity to testify, just as the defense attorney did while cross-examining the prosecution expert, it is essential that the expert is well prepared for trial.

The defense attorney and the expert typically meet one or more times before the DUI / DWI case goes to trial to review the expert's opinions about the particular drunk driving case. They will discuss any weaknesses in the case and areas where the prosecutor is likely to attack the expert's testimony. A skilled expert can anticipate these attacks by the prosecutor.

Because an experienced expert has testified in countless other trials, he or she thoroughly understands the issues involved in drunk driving cases. However, the prosecutor may occasionally score a point or two with the defense criminalist due to unavoidable flaws in the case. When that occurs, a good defense criminalist will testify in a way which allows the defense attorney to rehabilitate those points on re-direct examination.

A skilled driving under the influence defense expert is critical to the success of any drunk driving defense. A California lawyer who excels at defending DUI / DWI cases works with the most respected experts in the field, and will choose a defense expert who will have a strong impact on the jury and create reasonable doubt in the driver's guilt.