The efficacy of principles of persuasion and influence in aiding uncooperative individuals to become more cooperative has been well documented in the basic science literature. Less known is their effects in investigative interviews. This study examined the effects of liking (positivity) on informational elements produced in investigative interviews. Interviewees participated in a mock theft experiment and were randomly assigned to tell the truth or lie about the potential theft. Half the interviews were conducted in a high liking condition, the other half in a low liking condition. High liking produced less relevant details in both the interviews and written statements for truthtellers. Rapport had direct, positive effects on relevant and irrelevant details in the interviews but not the written statements and mediated the association between liking and relevant and irrelevant details in the interviews. Veracity condition moderated the association between liking and informational elements; liking had negative effects on relevant details for truthtellers in the interviews and written statements but positive effects on irrelevant details for liars in written statements. These findings suggested the need to examine how and when liking as a social influence tactic may be effective in investigative interviews.