Opinion of the Court
GIERKE, Judge:A general court-martial composed of officer members convicted appellant, contrary to his pleas, of stealing U.S. currency of a value greater than $100.00 (7 specifications) and wrongfully appropriating an American Express card, in violation of Article 121, Uniform Code of Military Justice, 10 USC § 921. The adjudged and approved sentence provides for a bad-conduct discharge, confinement for 60 days, partial forfeitures for 2 months, and reduction to the lowest enlisted grade. The Court of Criminal Appeals affirmed the findings and sentence in an unpublished opinion.
We granted review of the following issue:1
WHETHER THE MILITARY JUDGE ERRED TO THE PREJUDICE OF APPELLANT BY DENYING THE CHALLENGES FOR CAUSE.
Two challenges for cause are at issue in this case. The first involved a defense challenge of a lieutenant colonel who had previously served as a judge advocate and area defense counsel. The second, on which we turn our decision, involved Major (Maj) B, the wife of Office of Special Investigations Special Agent B, one of the agents responsible for investigating the crimes for which appellant was tried.
During voir dire, Maj B stated that she and her husband “don’t discuss cases.” She initially said that she had not heard her husband “make any references at all to this case.” When asked, however, if she had “heard him make any references at all that could be applied to this case,” she answered, “Yes.” Asked to elaborate, she testified:
It was a conversation on the telephone but I don’t know who he was talking to because I didn’t answer the telephone when we were at home. He made a comment like, “More money?” So when he got off the phone I said, “What are you talking about, ‘more money’?” I didn’t know who he was talking to. He said, “Oh, it is a case that is being worked on. Somebody said that this guy took more money.” That would be something that I might associate with this ease.
Defense counsel challenged Maj B for cause on the ground that she “is the wife of one of the case agents or the assistant case agent.... In this case, if for no other reason, we would think that the appearance aspect of this: the agent whose name is throughout this case file.” Defense counsel argued that Maj B should not sit on the court panel in order to keep the court-martial “free from substantial doubt as to reality [sic], fairness and impartiality.” Trial counsel did not dispute Special Agent B’s role in the investigation of this case, but informed the military judge that the prosecution “does not anticipate Agent [B]’s name coming up even once in this case.” The military judge denied the challenge, remarking that Maj B’s “answers were significantly direct, sincere, and that they reflected that she keeps apart then-two particular professional careers; that she knows nothing about this particular ease; [and] that she has not formed any opinion whatsoever in this particular case.” The military judge also ruled, “I don’t see a challenge for cause for ... [Maj B] based on the *231fact that she is the spouse of that particular agent.”
The record before us is unambiguous. Contrary to the assertion of our dissenting colleague that “there is no evidence in the record that ... [Special Agent B] was involved with appellant’s case,” 46 MJ at 235, counsel for both sides agreed, on the record, that Special Agent B was an assistant case agent in the investigation of the charges before the court-martial.
RCM 912(f)(1)(N), Manual for Courts-Martial, United States (1995 ed.), codifies a general ground for challenge applicable when a member “[s]hould not sit as a member in the interest of having the court-martial free from substantial doubt as to legality, fairness, and impartiality.” We have said that “[t]his general ground includes actual bias as well as ‘implied bias.’ ” United States v. Daulton, 45 MJ 212, 217 (1996), citing United States v. Harris, 13 MJ 288, 292 (CMA 1982). “The focus of the rule is on the perception or appearance of fairness.” United States v. Dale, 42 MJ 384, 386 (1995). The rule “reflects the President’s concern with avoiding even the perception of bias, predisposition, or partiality.” United States v. Lake, 36 MJ 317,323 (CMA 1993).
The issue in this case involves implied bias rather than actual bias. Although our standard of review is abuse of discretion for challenges based on actual bias as well as those based on implied bias, we give less deference to the military judge when implied bias is involved. See generally United States v. White, 36 MJ 284 (1993).
“A challenge for cause based on actual bias is ‘essentially one of credibility.’ ” Because of the military judge’s superior “opportunity to observe the demeanor of court members and assess their credibility during voir dire,” a military judge’s ruling on a challenge based on actual bias is given “great deference.” Daulton, 45 MJ at 217. “Implied bias,” on the other hand, “is reviewed under an objective standard____ Implied bias is not viewed through the eyes of the military judge or the court members, but through the eyes of the public.” Id. at 217. “[T]he military judge’s assessment of ... credibility ... is not dispositive on the issue of implied bias.” Id. at 218.
We hold that the military judge abused his discretion in denying the challenge of Maj B. Under an objective standard, there is a “substantial doubt” about the “legality, fairness, and impartiality” of a court-martial when a court member sits in judgment of a case investigated by her husband. Like the participation of the security police officer in Dale and the participation of the member whose sister and mother were victims of sexual abuse in Daulton, Maj B’s participation in a case investigated by her husband does not pass the test of public confidence contemplated by RCM 912(f)(1)(N). See RCM 912(f), Discussion (example of basis for challenge is that “the member ... is closely related to ... a witness in the case”); see also United States v. Glenn, 25 MJ 278, 280 (CMA 1987) (“We find it difficult to believe that either appellant or the public could be convinced that he received a fair trial when he was not apprised of the fact that a member of the staff judge advocate’s family was sitting on his court-martial.”).
Contrary to our dissenting colleague’s assertions, this decision is not a reflection on Maj B’s integrity, “a rejection of rehabilitation of potential court members,” 46 MJ at 232, or a holding that law enforcement personnel and their spouses are per se ineligible to sit as court members. We do not suggest that Maj B’s responses on voir dire were anything but completely honest and sincere. We are not holding that law enforcement personnel and their spouses are per se disqualified from sitting on courts-martial.
This case is not based on Maj B’s relationship with a person who happens to be in law enforcement. It is based on her relationship to a criminal investigator who investigated the charges in the specific ease before her. We hold only that Maj B’s participation in a case investigated by her husband would cause a reasonable member of the public to have “substantial doubt as to legality, fair*232ness, and impartiality” of the proceedings. ROM 912(f)(l)(N).
The decision of the United States Air Force Court of Criminal Appeals is reversed. The findings and sentence are set aside. The record of trial is returned to the Judge Advocate General of the Air Force. A rehearing may be ordered.
Judges SULLIVAN and EFFRON concur.
. We also granted review of the issue "[w]hether the military judge erred to the prejudice of appellant by instructing the members that a mistake of fact must be both honest and reasonable to be a defense to the specific-intent crimes of larceny and wrongful appropriation.” In light of our decision on the challenges for cause, we do not decide this issue.