Respecting a trial judge's credibility determination as it relates to potential bias or prejudice warranting recusal, the Tennessee Court of Criminal Appeals has clarified: To disqualify [a trial judge], prejudice must be of a personal character, directed at the litigant, "must stem from an extrajudicial source and result in an opinion on the merits on some basis other than what the judge learned from . . . participation in the case."Id.; see also United States v. Grinnell Corp., 384 U.S. 563, 583, 86 S.Ct. 1698, 1710, 16 L.Ed.2d 778 (1966); Houston v. State, 565 So.2d 277 (Ala.Crim.App.1990). . . . If the bias is based upon actual observance of witnesses and evidence given during the trial, the judge's prejudice does not disqualify the judge.