Expert witness testimony In some impaired driving cases, it may be

necessary to identify an expert witness. As a general rule, an expert is needed to

testify when there is a need to discuss scientific, technical, or other specialized knowledge as part of a hearing or case.

A key issue that is frequently raised in this situation is “who can be or should be called as a expert witness in the hearing”.

Expert witness testimony In making a determination about an “expert”

there are several factors to consider:

• First, there are court rules and case law in each state regarding what is required of an expert witness.

• Second, there is a requirement that the witness possess specialized knowledge that is relevant to the case. An expert can be someone that has, through education, experience, training, or observation, obtained the necessary knowledge on the topic over a reasonable period of time.

Expert witness testimony In selecting a suitable candidate for an

expert witness, it is also important to consider the subject matter that the expert will testify about.

The nature of the type of information that is needed by the court can help determine who is most suitable to provide testimony.

Expert witness testimony With regard to alcohol interlocks, if the

issue is one of tampering or circumvention, then perhaps a person who is familiar with the installation process or the downloading of the data would be an appropriate choice.

If the issue pertained to the meaning of the test results collected by the device, then a person with expertise in breath testing and analysis, or the management of the data may be more suitable.

Expert witness testimony Key questions to consider:

• What are the person’s qualifications or credentials? • Where did they gain their knowledge or

experience? Was the knowledge gained in a classroom or from hands-on experience working?

• Has the person conducted research in this area? What kind of research?

• Has the person authored peer reviewed articles or studies about alcohol interlock devices in leading or recognized journals?

• Does the person possess any licenses or certificates demonstrating their knowledge or expertise?

• Has the person previously been an expert witness in the courtroom on this issue?

Expert witness testimony Other issues that it may be useful to consider

include:

• How articulate is the witness?

• How effectively does the person present information?

• Is the witness an independent and/or unbiased witness?

• A person that is employed by or receives income from a alcohol interlock device manufacturer may not be considered independent and unbiased.

• It is important to determine whether this person has a vested interest in the outcome of the case.