In Barr v. Dai, 19-1155, and Barr v. Alcaraz-Enriquez, 19-1156, the U.S. Supreme Court will provide guidance on how appellate courts are to review the credibility of witnesses who appear before a lower tribunal. The guidance the court provides in those two cases will likely be narrow because they turn on the meaning of statutory language -- applicable only in a subset of immigration proceedings -- that erects "a rebuttable presumption of credibility on appeal" if the immigration judge does not "explicitly" make an "adverse credibility determination" regarding a witness. 8 U.S.C. Sections 1158(b)(1)(B)(iii) and 1229a(c)(4)(C).
But Dai and Alcaraz-Enriquez are of broader interest because they highlight a question that is asked in many appeals: How are appellate courts to review the credibility of witnesses?
Although witness credibility is generally considered to be a "question of fact," Cooley v. Superior Court, 29 Cal. 4th 228, 258 (2002), credibility is unlike other factual issues in two significant ways.
First, at trial, witness credibility is entrusted exclusively to the trier of fact -- whether that be a judge, a jury, or an administrative decision-maker -- before whom the witness appears. People v. Barnes, 42 Cal. 3d 284, 303 (1986); United States v. Ginn, 87 F.3d 367, 369 (9th Cir. 1996). This means "secondary evidence" regarding witness credibility is generally not admissible. Thus, while experts are usually allowed to opine on "ultimate issue[s]" in a case, Fed. R. Evid. 704(a); Cal. Evid. Code Section 805, they "may not give an opinion whether a witness is telling the truth," People v. Coffman and Marlow, 34 Cal. 4th 1, 82 (2004); United States v. Benally, 541 F.3d 990, 995 (10th Cir. 2008). This is because it is the jury's province "to determine credibility"; encroaching upon that sacred territory is a no-no. United States v. Bighead, 128 F.3d 1329, 1331 (9th Cir. 1997); Johnstone v. Morris, 210 Cal. 580, 589-90 (1930). For much the same reason, attorneys may "'not ask one witness to comment on the veracity of the testimony of another witness.'" United States v. Geston, 299 F.3d 1130, 1136 (9th Cir. 2002); People v. Chatman, 38 Cal. 4th 344, 383-84 (2006).
Second, on review, appellate courts accord almost near-absolute deference to a lower tribunal's credibility findings. A lower tribunal's resolution of factual questions are accorded deference -- review is only for "clear error" in federal court, Fed. R. Civ. P. 52(a)(6); Oakland Bulk & Oversized Terminal, LLC v. City of Oakland, 960 F.3d 603, 612 (9th Cir. 2020), and for "substantial evidence" in California, In re White, 9 Cal. 5th 455, 470 (2020). But a lower tribunal's credibility findings are accorded "special deference." In re Hardy, 41 Cal.4th 977, 993 (2007); Kidd v. Illinois State Police, 167 F.3d 1084, 1097 (7th Cir. 1999). In federal court, courts apply the more deferential, "clear error," standard to credibility findings that insulates them entirely if, say, they boil down to a choice between which of two conflicting witnesses to believe. Earp v. Davis, 881 F.3d 1135, 1145-46 (9th Cir. 2018). In California, a credibility finding will be overturned only if testimony is "demonstrabl[y] fals[e]," usually because it is either (1) "physically impossible," or (2) "inherently improbable[,] and such inherent improbability plainly appears." People v. Hovarter, 44 Cal. 4th 983, 996 (2008); Fuentes v. AutoZone, Inc., 200 Cal. App. 4th 1221, 1233 (2011).
So why do credibility findings get such a hands-off approach from appellate courts? Vantage, vantage, vantage.
The court in Meiner v. Ford Motor Co., 17 Cal. App. 3d 127, 140 (1971), may have said it best: "A written transcript of testimony is but a pallid reflection of what actually happens in a trial court. The best and most accurate record is like a dehydrated peach; it has neither the substance nor the flavor of the fruit before it was dried." (Quotations and citations omitted.)
Because the trier of fact is the only one who has observed the testimony in all of its first-hand juiciness, only the trier of fact "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." Anderson v. Bessemer City, 470 U.S. 564, 575 (1985).
But is this degree of deference appropriate?
If the role of intermediate appellate courts is to correct errors in the verdicts and rulings of trial courts, does too much deference to credibility findings prevent the appellate courts from fulfilling that role if the error is in the trier of fact's assessment of witness credibility?
And if we assume that lower tribunals are not perfect, and thus do sometimes make errors in assessing credibility, what can appellate courts realistically do to find and correct those errors?
One possibility is for the appellate courts to apply varying levels of scrutiny to credibility findings. Credibility determinations are not monolithic; they are more like a molecule than an atom insofar as they can be broken down into smaller components. Specifically, witness credibility can be undermined (or buttressed) by (1) the content of the witness' testimony, (2) the witness' motive(s), (3) the witness' character for truth and veracity, and/or (4) the witness' demeanor. Content refers to the substance of the witness' testimony, and whether it is contradicted (or corroborated) by other evidence presented to the trier of fact, by the witness' prior statements, and by deficiencies in the witness' capacity to perceive, recollect or communicate. Motive refers to the witness' reasons (or lack of reasons) to shade his or her testimony, and can include bias. Character refers to the witness' propensity for telling the truth or lying. Demeanor refers to the witness' affect while on the stand. See generally Cal. Evid. Code Sections 780, 786; Fed. R. Evid. 608.
Courts have already expressed some willingness to probe credibility findings more deeply when they rest on the content of the witness' testimony, such as when that content is "contradict[ed]" by "[d]ocuments or objective evidence," Anderson, 470 U.S. at 575.
Courts have simultaneously expressed great reluctance to second guess credibility findings that rest on demeanor due to its ineffable nature. This explains why some courts are willing to use greater scrutiny when content is presented solely on affidavits or declarations rather than through live testimony. Compare In re Resendiz, 25 Cal. 4th 230, 249 (2001) (so holding) with In re Marriage of Nurie, 176 Cal. App. 4th 478, 492 (2009) (disagreeing).
What degree of scrutiny should appellate courts apply to credibility findings based solely on the witness' motive or character, or to findings based on a combination of components? And what weight, if any, should courts give to the empirical research indicating that witness demeanor is a poor gauge for assessing truth-telling? See Morales v. Artuz, 281 F.3d 55, 61 & nn.3&4 (2d Cir. 2002) (collecting sources); State v. Christensen, 929 N.W.2d 646, 658 n.1 (Iowa 2019) (same).
These questions would need to be answered if appellate courts considered this possibility.
Another possibility is to limit the greater deference reserved for credibility findings to a trier of fact's express credibility findings. Implied credibility findings are commonplace: A jury that finds a defendant guilty of assault despite his girlfriend's testimony that he would not, as Jay-Z would say, bust a grape in a fruit fight, constitutes an implied finding that the girlfriend was not credible. And implied findings -- at least where they are necessarily implied by the ruling -- are typically treated like express findings. People v. Harris, 234 Cal. App. 4th 671, 695 (2015); United States v. Cisneros-Rodriguez, 813 F.3d 748, 758 (9th Cir. 2015). Except where general jury verdicts are the rule (such as in criminal cases), appellate courts could insist that the trier of fact make express credibility findings before such findings would warrant special deference. They could also require the trier of fact to justify that finding, which would give the appellate court more to review. Compare Kalubi v. Ashcroft, 364 F.3d 1134, 1137-38 (9th Cir. 2004) (requiring justification for immigration judge's finding); Rashad v. Sullivan, 903 F.2d 1229, 1231 (9th Cir. 1990) (same, for administrative law judge's finding) with Meiner, 17 Cal. App. 3d at 141-42 (disavowing any requirement for a justification because it would require the trier of fact "to explain the unexplainable").
Whatever innovations we come up with, what is certain is that the court system will always need some effective mechanism for making -- and reviewing -- findings that the witness is a "liar, liar," well, you know the rest...