Language of a Liar

Lying suspects tend to deny guilt with specific language such as, in a fatal shooting, "I didn't do it with that gun." Truthful suspects, however, tend to voice general denials like "I never shot her or anyone else in my life." Truthful suspects are not afraid to use harsh, realistic words, such as "steal," "rape," "kill," "rob," "stab," but the deceptive ones usually avoid such language in order to assuage their guilty feeling. Even when less harsh terms are used, the liar's tone of voice will sound weak, in contrast to the strong utterance of a truthful suspect.

Fred E. Inbau, Criminal Interrogation and Confessions, 1986