Expert Witnesses in Atlanta DUI Cases

Expert witnesses are allowed to testify during trial in Georgia to help the prosecution educate jurors about the evidence that each side wants them to consider. For example, experts can talk about field sobriety testing and the studies that have been done to correlate the results of field sobriety tests to proof of impairment. Additionally, experts can testify to the jury about the effects of certain medications or about how the crime lab operates its testing procedures. If the testimony relates to the case presented, the court will usually allow a qualified expert to testify about it.

Working with experts is a skill that is developed over time as an Atlanta DUI attorney has be able to guide the experts through the evidence and through the testimony, without being derailed through the prosecution’s objections for leading the witness. It also is important that the attorney knows what types of questions to ask the expert and has prepared the expert with the foundations of the defense the attorney is using with the jury.

Introducing a Witness at Trial

The first thing that happens at trial when an expert is involved is that the attorney who is putting up the expert must take the expert through a series of questions designed to establish that the person is in fact an expert in the area that they are going to testify about. Next, the defense attorney or the prosecutor will get the expert to talk about his or her experiences to establish in the jury’s mind that the person is an expert as well.

From there, the lawyer will ask the expert to talk about the evidence in the particular case and give his or her opinion about it. The other side is then allowed to cross examine that particular expert and will try to bring up problems with the expert’s testimony or the expert’s opinion.

How Much Weight is The Expert’s Testimony Given?

How much weight the jury gives the expert’s testimony is a question that the jury is allowed to decide for themselves. They many find certain experts to be more credible than others. They may find certain experts to be more knowledgeable than others, but the jury decides how much weight to give on the expert’s testimony.

Prosecutorial Witnesses

Quite often, the prosecution calls drug recognition experts to testify. These are police officers who have specialized training in the detection of drugs and other impairing substances. Additionally in DUI cases, the prosecution often calls forensic chemists to testify about the effects of drugs and  about how the crime lab tests blood, urine, or other substances.

What Can a Defense Attorney Do To Challenge The Prosecution’s Witnesses?

Many times, trials become what people refer to as a battle of the experts. The prosecution brings in more experts to testify about the effects of drugs and about how the drugs are tested. Then the defense is also allowed to bring in experts to testify about the effects of drugs and how drugs are tested. In a homicide case, for example, an expert may testify about the GBI crime lab’s records. Only an expert could read through those records and testify to what those GBI crime lab records meant.

Defense Witnesses

There are several types of experts that may be used by the defense in DUI cases in Atlanta area. The first type is former law enforcement officers. These are officers who have worked in state patrol or other law enforcement agencies in Georgia, have received all the training that the officers receive, and in many cases made hundreds, if not thousands, of DUI arrests while they were serving as law enforcement officers. Their testimony can be very important to establish to the jury whether the officer who made the arrest was following proper procedures and did the field sobriety test correctly.

The second type of expert that may be used are chemists or other scientific experts who can testify about breath testing, blood testing, and other crime labs procedures.

The third type of experts that are commonly brought in are specialists in accident reconstruction.