What does successful interrogation primarily rely on?

Successful interrogation primarily relies on questioning and observation because these techniques allow the interrogator to gather crucial information and assess the subject's responses carefully. By asking targeted questions, the interrogator can delve deeper into the subject's story, identify inconsistencies, and encourage them to reveal more details. Observation plays a vital role in assessing non-verbal cues, such as body language and facial expressions, which can provide additional insight into the subject's truthfulness and emotions. Together, effective questioning and keen observation create an environment where the subject may feel compelled to divulge information that may not be initially forthcoming.

In contrast, while psychological tactics, legal threats, and promises of leniency may have their places in specific scenarios, they are not the foundational elements of a successful interrogation strategy. Focusing on direct communication and the ability to read a suspect's behavior tends to yield more reliable results in obtaining information.