U.S. 418, 423-24, 99 S.Ct. 1804, 60 L.Ed.2d 323 (1979) (noting that the “clear and convincing” standard of proof is an “intermediate standard” that falls between a “mere preponderance of the evidence” and “beyond a reasonable doubt”); see also Direx Israel, Ltd. v. Breakthrough Med. Corp., 952 F.2d 802, 810 n. 7 (4th Cir.1992) (same).
On appeal, we review the district court’s factual findings for clear error and its legal conclusions de novo. See Fed. R.Civ.P. 52(a)(6); United States v. White, 620 F.3d 401, 410 (4th Cir.2010); United States v. Cox, 964 F.2d 1431, 1433 (4th Cir.1992). “A finding is ‘clearly erroneous’ when although there is evidence to support it, the reviewing court on the entire evidence is left with the definite and firm conviction that a mistake has been committed.” United States v. United States Gypsum Co., 333 U.S. 364, 395, 68 S.Ct. 525, 92 L.Ed. 746 (1948); Easley v. Cromartie, 532 U.S. 234, 242, 121 S.Ct. 1452, 149 L.Ed.2d 430 (2001) (internal quotation marks omit ted). “This standard plainly does not entitle a reviewing court to reverse the finding of the trier of fact simply because it is convinced that it would have decided the case differently.” Anderson v. Bessemer City, 470 U.S. 564, 573, 105 S.Ct. 1504, 84 L.Ed.2d 518 (1985). “If the district court’s account of the evidence is plausible in light of the record viewed in its entirety, the court of appeals may not reverse it even though convinced that had it been sitting as the trier of fact, it would have weighed the evidence differently.” Id. at 573-74, 105 S.Ct. 1504.
“When findings are based on determinations regarding the credibility of witnesses,” we give “even greater deference to the trial court’s findings.” Id. at 575, 105 S.Ct. 1504.
[0]nly the trial judge can be aware of the variations in demeanor and tone of voice that bear so heavily on the listener’s understanding of and belief in what is said. This is not to suggest that the trial judge may insulate his findings from review by denominating them credibility determinations, for factors other than demeanor and inflection go into the decision whether or not to believe a witness. Documents or objective evidence may contradict the witness’ story; or the story itself may be so internally inconsistent or implausible on its face that a reasonable factfinder would not credit it. Where such factors are present, the court of appeals may well find clear error even in a finding purportedly based on a credibility determination. But when a trial judge’s finding is based on his decision to credit the testimony of one of two or more witnesses, each of whom has told a coherent and facially plausible story that is not contradicted by extrinsic evidence, that finding, if not internally inconsistent, can virtually never be clear error.
Id. (citations omitted). As with lay witnesses, “[e]valuating the credibility of experts and the value of their opinions is [also] a function best committed to the district courts, and one to which appellate courts must defer,” and we “should be especially reluctant to set aside a finding based on the trial court’s evaluation of conflicting expert testimony.” Hendricks v. Central Reserve Life Ins. Co., 39 F.3d 507, 513 (4th Cir.1994).
B.
Here, there is no dispute that Hall engaged in past acts of child molestation, as evidenced by his prior convictions in 1989 and 1999. Thus, the district court found that the government established the first element of sexual dangerousness by clear and convincing evidence. See 18 U.S.C. § 4247(a)(5). There is also no dispute that