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Expert Witnesses in Baltimore DUI Cases

In many criminal cases, expert witnesses are often called upon to testify in court. The prosecution may call medical professionals to explain the blood test results. When there is any kind of technical issue in the case that is a very fact-specific analysis, for example, an accident reconstructionist, the state may need to call an expert to explain that. At the same time, a DUI lawyer in Baltimore can also call upon expert witness testimony as support for a defense against a driving under the influence charge.

Importance of Expert Testimony in Baltimore DUI Cases

The weighing of expert testimony is something that comes down to the finder of facts. If the case is a bench trial; the finder of facts is the judge. If the case is a jury trial, the jury is the finder of facts. Either the judge or the jury decides how much weight to give to the expert testimonies. That is based on their demeanor on the stand; how well they answered questions; and how well they do under cross-examination.

Anytime one side calls an expert, the other side has the opportunity to cross-examine that expert. For example, if the prosecutor calls an expert witness to testify, when it is time for a Baltimore DUI lawyer to cross-examine the expert witness, the lawyer can ask questions to make it appear that they don’t know what they’re talking about or their opinion isn’t as certain as they make it seem on the witness stand.

Role of Expert Witnesses in Prosecution’s Case

There are three kinds of expert witnesses in a Baltimore prosecution’s DUI case. One is a police expert who is an ordinary officer that received some type of specialized training. This is training to administer the field sobriety test, particularly the horizontal gaze nystagmus test. The officer must be admitted in expert witness before he can testify as to the results of the field sobriety test.

The other kind of expert witness is a medical professional; someone the state calls on to explain blood test results. For example, in a DUI drug case, the state provides an expert witness to explain to the court what the blood results actually mean. There are no presumptions that are automatically given to a blood test result. In contrast, for a DUI for alcohol, if the test was administered on a certified machine by a certified operator within the rules set up by the toxicologist, the state does not need to provide an expert to explain that test. There is a presumption that a certain result is equivalent to a certain level of impairment.

In drug cases, there are no presumptions like that. In many blood test result cases, particularly hospital blood draws, there are no presumptions like that. Thus, the state needs to provide an expert to explain the results of the chemical test.

How a Lawyer Can Refute Government’s Expert Witnesses

There are two ways a Baltimore DUI attorney can challenging the claims of government experts. One is by attacking that individual’s expertise. That could include suggesting that their qualification shouldn’t allow them to be considered as an expert; they lack the requisite training or experience to be an expert in that subject area.

The other way to challenge an expert’s claims is for the defense team to have their own expert. If the state brings in a toxicologist saying that this blood result means this level of impairment, the defense may bring in another expert saying the blood result doesn’t necessarily imply that at all. An attorney can either challenge the state’s expert directly or bring in another expert to do it.

The quality a defense’s expert witnesses can really decide a case, especially in a jury trial where the jury follows the expert opinion based on who they like or trust more. Having learned who has good experts can have a significant impact on the outcome of the case, which is why it is so important to seek the help of an established local attorney.