The Art of Cross-Examination - Legal Interrogation Techniques - By Francis L. Wellman of The New York Bar. Interrogation (also called questioning) is interviewing as commonly employed by law enforcement officers, military personnel, and intelligence agencies with the goal of eliciting useful information. Interrogation may involve a diverse array of techniques, ranging from developing a rapport with the subject, to outright torture. It needs but the simple statement of the nature of cross-examination to demonstrate its indispensable character in all trials of questions of fact. No cause reaches the stage of litigation unless there are two sides to it. If the witnesses on one side deny or qualify the statements made by those on the other, which side is telling the truth? Not necessarily which side is offering perjured testimony,