Many DUI and DWI defense cases depend on expert witnesses. To be sure, there are many cases where a skilled defense lawyer can obtain a dismissal or an acquittal without an expert, many cases revolve around the validity and credibility of field sobriety tests and chemical tests. Expert witnesses can demonstrate that the proper equipment or procedures weren’t used, that tests were not administered correctly, and that there are alternative explanations for a high test result. The type of expert depends on the specific test used against you.
Defense experts may also testify regarding the operation of the car, truck, or other vehicle. Experts may also testify about proper police procedures independent of any chemical tests.
What does it mean to be an expert witness?
Maryland law provides that testimony by expert witnesses can be introduced into court, as an opinion or otherwise:
“If the court determines that the testimony will assist the trier of fact to understand the evidence or to determine a fact in issue. In making that determination, the court shall determine:
(1) Whether the witness is qualified as an expert by knowledge, skill, experience, training, or education,
(2) The appropriateness of the expert testimony on the particular subject
(3) Whether a sufficient factual basis exists to support the expert testimony.
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There are specific Maryland rules that govern when and how experts can give their opinions, the right of legal counsel to object that the witness is an expert witness, and the right to question the expert witness. The weight that is given to expert testimony and the ability to render an opinion separates expert witnesses from non-expert witnesses (lay witnesses).
Generally, our DUI defense lawyers question the credentials of expert witnesses introduced by the prosecution and cross-examine their statements and opinions.
Drew Cochran, Attorney at Law works with expert witnesses who have the proper certifications, are experienced in the area of law (such as breathalyzer machines), and are comfortable testifying in court and explaining complex principles in a way a judge and jury can understand. We also review whether the expert we choose has references, is respected in their field, and has written publications in their field. A good expert witness should also be able to give articulate answers and keep their composure when cross-examined by a prosecutor.
Expert witnesses in DUI cases must have scientific and technical knowledge. They typically testify in court, though sometimes written reports may be used if both parties agree. Expert opinions must be fact-based and unbiased.
Who are the expert witnesses for the government in a DUI case?
In many DUI cases, a police officer is the only witness. Most police officers are “fact witnesses.” They can testify to what they observed, what field sobriety tests they gave, what breath test they gave you, how they administered these tests, and the results of these tests. Some law enforcement have special expertise in a certain area of law enforcement.
Normally, the officer will be asked by the prosecutor to testify about the specific field sobriety tests they gave and how you performed on each test, the specific breath test they gave you, and the results of that test. We understand what factual testimony an officer can give about field sobriety and breath tests, when expert testimony is required, whether the officer can qualify as an expert witness, and when another type of test expert is required.
If a blood test is required, a health professional at a hospital must administer the test and testify about the results as an expert witness.
Which expert witnesses testify for the defense in DUI cases?
Our Annapolis DUI and DWI defense lawyers may request that expert witnesses testify on your behalf – at a suppression hearing or at your criminal trial. Some of the expert witnesses we may call include:
- A field sobriety test expert. This expert can testify which tests (horizontal gaze nystagmus test, walk and turn test, and one leg stand test) should be given and which tests are inadmissible. The expert will testify about the proper procedures for giving these tests and explain, when applicable, why the police officer who stopped you failed to follow these procedures.
- A breathalyzer test expert. This expert may testify about some or all of the following:
- Whether the machine that was used was an approved device.
- Whether the machine was properly examined and calibrated in the proper time frame.
- Whether the police officer followed proper procedures. These may include:
- Having grounds to ask you to take the test
- Giving you the test within the proper time from when you were stopped (generally you must be tested within two hours of the arrest)
- Explaining the rules for taking the test
- Observing you before giving you the test
- Obtaining the proper number of samples
- Other requirements
- Your family doctor or another medical expert. We may call a healthcare professional to explain what other reasons might show a high blood alcohol concentration (BAC) level and why those reasons apply to your medical situation. For example, diabetes (type 1 or type 2), Gastroesophageal reflux disease (GERD), certain diseases, or other factors may lead to an incorrect BAC result.
At Drew Cochran, Attorney at Law, we’ve been fighting for criminal defendants for more than 20 years. Criminal defense work is all we do. Don’t assume you don’t have a defense. The government often doesn’t have as strong a case as you think. There are many defenses our Annapolis and Ellicott City DUI and DWI lawyers can assert. We work with expert witnesses, including breathalyzer experts and medical professionals. If you’ve been arrested for drunk driving, call me now or fill out my contact form to schedule a consultation.
And remember: Keep Calm – and Call Drew.
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