Experts are allowed to give opinion testimony from which a non-expert witness may be prohibited.
Experts are qualified according to a number of factors, including but not limited to, the number of years they have practiced in their respective field, work experience related to the case, published works, certifications, licensing, training, education, awards, and peer recognition. They may be called as upon as consultants to a case and also used to give testimony at trial. Once listed as a witness for trial, the materials they rely upon in forming an opinion in the case is subject to discovery by the opposing parties.
In court, the party offering the expert must lay a foundation for the expert's testimony. Laying the foundation involves testifying about the expert's credentials and experience that qualifies him/her as an expert. Sometimes the opposing party will agree to the expert's qualifications in the interests of judicial economy. Expert testimony is subject to attack on cross-examination in the form of questioning designed to bring out any limitations in the witness's qualifications and experience, lack of witness's confidence in his opinions, lack of the preparation done, or unreliability of the expert's sources, tests, and methods, among other issues.
NMG doctors often serve as expert witnesses and may provide testimony regarding the following issues, among others: