Criteria-Based Content Analysis (CBCA) is a tool to assess the veracity of written statements, and is used as evidence in criminal courts in several countries in the world. CBCA scores are expected to be higher for truth tellers than for liars. The underlying assumption of CBCA is that (i) lying is cognitively more difficult than truth telling, and (ii) that liars are more concerned with the impression they make on others than truth tellers. However, these assumptions have not been tested to date. In the present experiment 80 participants (undergraduate students) lied or told the truth about an event. Afterwards, they completed a questionnaire measuring “cognitive load” and “tendency to control speech”. The interviews were transcribed and coded by trained CBCA raters. In agreement with CBCA assumptions, (i) truth tellers obtained higher scores than liars, (ii) liars experienced more cognitive load than truth tellers, and (iii) liars tried harder to control their speech. However, cognitive load and speech control were not correlated with CBCA scores in the predicted way.