Expert opinions are necessary in most automobile accident or collision cases and workers compensation cases. It is necessary to have expert witnesses give opinions on how the accident happened and the nature and extent of the injuries. Expert witnesses usually have advanced degrees in engineering or medicine, education as well as practical work experience. Sometimes an expert witness has only work experience and may be the most persuasive. The classic example from popular culture is the female auto mechanic expert played by Marisa Tomei in My Cousin Vinny.
Usually, witnesses can testify only to facts they know. But, a witness with expertise in a specialty like accident reconstruction or medicine may give an opinion in that calling specialty. In determining the weight to be given an opinion, the jury considers the qualifications and credibility of the expert and whether reasons for the opinion are based on facts in the case. Opinion evidence can help the jury reach a conclusion, but it is not bound by any expert's opinion. In resolving conflicts in expert testimony, the jury weighs the different expert opinions against each other and considers the qualifications and credibility of the experts and the reasons and facts supporting their opinions.
In addition to doctor's live testimony, sometimes we submit into evidence portions of published articles written by recognized experts. This evidence is not received to establish that the views expressed by the author are undisputed truths or absolute standards. The author's views should be considered as any other expert witness' opinion. The jury is not bound by the opinions expressed by the author any more than they are not bound by the opinion of any other expert witness.
Often during the trial, an expert witness is told to assume certain facts and asked for an opinion based upon the assumed facts. Milbauer v Transport, 56 Wis 2d 860 (1973). This is called a hypothetical question. The jury can consider the opinion in answer to the hypothetical question only if it believes the assumed facts upon which it is based. If the jury finds that the assumed facts in the hypothetical question have not been proved, it must not give any weight to the opinion.
McCormick Law Office in Milwaukee Wisconsin always uses expert witnesses to prove medical causation and permanent injury when appropriate. Attorneys get the best results from expert doctor opinions that are honest and trustworthy, based on solid facts. Cases involving neck or back herniated discs resulting in cervical surgery or lumbar fusion surgery must have qualified opinions. Treating surgeons are the best evidence, but at times we retain independent physicians to review the records, examine our client and write a report when expert opinions are necessary.