Again, we do not disagree with that general proposition. But before a plaintiff can rely on circumstantial evidence or the process of elimination Truck urges on us here, the plaintiff must at least present evidence to show why the defendant's product should not be among the possible causes to be eliminated. See, e.g., Hollander v. Sandoz Pharm. Co., 289 F.3d 1193, 1211 (10th Cir. 2002) (requiring plaintiffs' experts to "rule in" the defendant's drug "as a scientifically plausible cause"); Franklin v. Skelly Oil Co., 141 F.2d 568, 570-71 (C.C.A. 10 Cir. 1944) ("It is not sufficient to show a set of circumstances bringing the theory of appellants within the realm of possibilities . . ."); Kaiser Found. Health Plan v. Sharp, 741 P.2d 714, 719 (Colo. 1987) (en banc) ("[T]he plaintiff must establish causation beyond mere possibility or speculation."). Requiring Truck to show that the ballast was capable of causing the harm of which they complain conforms not only with the established law of Colorado and this circuit, but with the investigatory standards of the National Fire Protection Association, see NFPA Guide for Fire and Explosion Investigation 921 § 18-4.1 ("Before it can be concluded that a particular appliance has caused the fire, it should first be established how the appliance generated sufficient heat energy to cause ignition.").

This requirement helps to ensure that the report is reliable. See Franklin v. Skelly Oil Co., 141 F.2d 568, 572 (10th Cir. 1944). The Shooting Review Board was a properly constituted body of the Department of Public Safety pursuant to Okla. Stat.Ann. tit. 47, § 2-103 (Commissioner of Public Safety has authority to organize department in manner he "may deem necessary").

II Defendants argue that the trial court erred in refusing to grant their motion for a judgment n.o.v. Relying on Franklin v. Skelly Oil Co., 141 F.2d 568 (10th Cir. 1944),inter alia, they assert that plaintiff's evidence relating to product alteration by defendants was essentially based on "an attenuated string of palpably unreasonable speculations" by plaintiff's "expert," George Greene. Brief of Defendants/Appellants 23, 34. In Franklin we stated:

Sustaining admissibility are such cases as United States v. Dumas, 149 U.S. 278, 13 S.Ct. 872, 37 L.Ed. 734 (1893), statement of account certified by Postmaster General in action against postmaster; McCarty v. United States, 185 F.2d 520 (5th Cir. 1950), reh. denied 187 F.2d 234, Certificate of Settlement of General Accounting Office showing indebtedness and letter from Army official stating Government had performed, in action on contract to purchase and remove waste food from Army camp; Moran v. Pittsburgh-Des Moines Steel Co., 183 F.2d 467 (3d Cir. 1950), report of Bureau of Mines as to cause of gas tank explosion; Petition of W----, 164 F. Supp. 659 (E.D.Pa. 1958), report by Immigration and Naturalization Service investigator that petitioner was known in community as wife of man to whom she was not married. To the opposite effect and denying admissibility are Franklin v. Skelly Oil Co., 141 F.2d 568 (10th Cir. 1944), State Fire Marshal's report of cause of gas explosion; Lomax Transp. Co. v. United States, 183 F.2d 331 (9th Cir. 1950), Certificate of Settlement from General Accounting Office in action for naval supplies lost in warehouse fire; Yung Jin Teung v. Dulles, 229 F.2d 244 (2d Cir. 1956), `Status Reports' offered to justify delay in processing passport applications. Police reports have generally been excluded except to the extent to which they incorporate firsthand observations of the officer.

Rule 26, Fed.Rules Crim. Proc., 18 U.S.C.A. For purposes of applying the rule no difference has been recognized between documents of federal, state and county governments. See Hedrick v. Hughes, supra; Sandy White v. United States, 164 U.S. 100, 17 S.Ct. 38, 41 L.Ed. 365; E.K. Hardison Seed Co. v. Jones, 6 Cir., 149 F.2d 252; Franklin v. Skelly Oil Co., 10 Cir., 141 F.2d 568, 153 A.L.R. 156; Gilbert v. Gulf Oil Corp., 4 Cir., 175 F.2d 705; Rollins v. Board of Commissioners, 8 Cir., 90 F. 575. Generally stated, the rule is that all documents prepared by public officials pursuant to a duty imposed by law or required by the nature of their offices are admissible as proof of the facts stated therein.

“It is not sufficient to show a set of circumstances bringing [a] theory of [causation] within the realm of possibilities.” Franklin v. Skelly Oil Co., 141 F.2d 568, 570-71 (10th Cir. 1944).

Because of the fact-intensive nature of this analysis, the decision whether to admit administrative reports is within the trial court's sound discretion. See Hall v. W. Prod. Co., 988 F.2d 1050, 1057 (10th Cir. 1993); Franklin v. Skelly Oil Co., 141 F.2d 568, 572 (10th Cir. 1944) ("The search is for truth and the trial court is the first and best judge of whether tendered evidence meets that standard of trustworthiness and reliability which will entitle it to stand as evidence of an issuable fact, absent the test of cross-examination."). ANALYSIS

This is designed to obviate the constant attendance of public officers in court to prove routine matters, Wigmore, Evidence, (3d Ed.,) § 1631, whereas in the instant case the signers of the letter were available as witnesses and present in court. Furthermore, as pointed out in Franklin v. Skelly Oil Co., 10 Cir., 141 F.2d 568, 572, 153 A.L.R. 156 ‘ expressions of opinion and conclusions on causes and effects based upon factual findings are not always admissible as public records, especially when it is shown either that the conclusion or opinion which the statement purports to convey would not be admissible in evidence if tendered by the direct testimony of the maker, or if the denial of the right of cross-examination could result in the perversion of the rule of trustworthiness and reliability. See Kansas City Life Ins. Co. v. Meador, 186 Okl. 397, 98 P.2d 20.

The advisory committee note states that one factor to be considered was "whether a hearing was held and the level at which [the hearing] was conducted." F.R.E. 803 advisory committee's note (citing Franklin v. Skelly Oil Co. , 141 F.2d 568 (10th Cir. 1944) ). Franklin , in turn, makes clear that the type of hearing that may be an indicia of trustworthiness is a hearing held by the issuing agency that serves as a basis for the agency's findings in the report.

"At the request of the defendant, Nu-Gas Company, I charge you that a retail dealer, who sells goods made by another ordinarily is not held to the same inspection as the manufacturer, but must exercise the care and competence of a reasonable dealer as to any defects which he has an opportunity to discover; the care required of such a seller at retail is only that of a reasonable man under the circumstances; such care does not extend beyond the reasonable examination which experience would indicate to the retail dealer is necessary, along with the investigation of any unusual condition that may be apparent." In support of this assignment, plaintiff's counsel cites Rulane Gas Company v. Montgomery Ward Co., 231 N.C. 270, 56 S.W.2d 689 and Franklin v. Skelly Oil Co., 10 Cir., 141 F.2d 568, 153 A.L.R. 156. In the case of Rulane Gas Company v. Montgomery Ward Co., the retailer, Montgomery Ward, had made specific representation to the purchaser that a stove sold by it could be used for Rulane (propane) gas, when in fact it was not adapted to such use, even after the dealer had made certain adjustments to the equipment.