Expert witnesses are at once detested and treasured. The scorn is significant because of the increasingly prominent role experts play in both civil and criminal litigation. Experts are seen as mercenaries, prostitutes or hired guns, witnesses devoid of principle who sell their opinions to the highest bidder. Experts are not impartial professionals who explain difficult concepts to the trier of fact. Rather, experts become advocates for the side who hired them. The consequences of this role change are not desirable: experts testify to matters beyond their expertise, render opinions that are unreliable, speculative or outside what the experts would be willing to say in their own disciplines, and misrepresent the certainty of many scientific principles they rely on and conclusions they reach. Unfortunately, experts are rarely held accountable for their errors on the witness stand: they testify without risk of perjury prosecutions or sanctions from their professional peers. The disdain for experts comes from all quarters: judges, lawyers, commentators, politicians, the media, and even experts themselves.
L. T. Perrin,
Expert Witness Testimony: Back to the Future,
U. Rich. L. Rev.
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