An experiment examined how veracity, modality, and experimenter sanctioning of deception influenced credibility assessments made by professionals who conducted interviews face-to-face (FtF) or by video conference (VC). Participants (N = 243) completed a trivia game with a confederate who encouraged cheating. Some lies were sanctioned by the experimenter and others were unsanctioned. The professional interviewers educed a high number of confessions in the sanctioned (58%) and unsanctioned (79%) lie conditions. Overall accuracy of the interviewers ranged from 45% to 67%. Interviewers were more accurate when judging veracity FtF than in VC. Those in the deceptive VC conditions (especially sanctioned liars) were rated by interviewers as more dominant, involved, relaxed, and active than those in the FtF condition, revealing that modality affected deceivers’ demeanor.