Dissenting
I respectfully dissent. While I agree with Parts I-III, and Parts V-VII of the majority opinion, I disagree as to Part IV and to the ultimate judgment of this Court.
Expert witnesses are a vital part of most negligence actions because of the peculiar legal concept involved, "standard of care". When one fails to observe a standard of care in a particular situation, one is negligent. Put another way, negligence is the failure to do what a reasonable and prudent person would ordinarily have done under the circumstances of the situation, or doing what such a person under the *12existing circumstances would not have done. Baltimore &. P.R. Co. v. Jones, 95 U.S. 439, 24 L.Ed. 506 (1877), Owl Drug Co. v. Crandall, 52 Ariz. 322, 80 P.2d 952 (1938), Stewart v. Smith, 68 Ariz. 91, 200 P.2d 353 (1948).
The key words in the above definition are, "under the circumstances." One cannot determine what a reasonable person would do under certain circumstances, unless one has a basis of comparison.
The testimony of the expert witnesses in this case was for the purpose of forming such a comparison. It was a vital part of the plaintiffs' case. Without a basis of comparison with other jails and procedures, I don't see how the jurors could have formed an opinion as to the standard of care for the jail facility in question.
I would therefore REVERSE the judgment of the District Court.