What is the most crucial difference in legal admissibility between HUMINT and SIGINT evidence in a domestic terrorism case?

The most crucial difference lies in the requirements for source protection and potential challenges to chain of custody. HUMINT (Human Intelligence), which is information gathered from human sources, is often subject to stricter scrutiny regarding the reliability and potential bias of the source. Admissibility hinges on establishing the credibility of the informant and protecting their identity, which can be challenging without compromising the case. SIGINT (Signals Intelligence), which is information gathered from electronic signals, is generally more reliable in terms of source integrity but faces challenges related to the legality of the collection method under laws like FISA (Foreign Intelligence Surveillance Act). The process by which the signals were intercepted and analyzed must be meticulously documented to ensure it meets legal standards. Therefore, while HUMINT struggles with source reliability, SIGINT's primary hurdle is demonstrating lawful collection and preservation of the electronic data.