The Springfield Three case is unusual because it presents an inversion of the standard cold case problem: investigators have a named individual who claims knowledge of the crime but cannot be compelled to share it, and they have no physical evidence to use as leverage. Cox was never charged and died in 2015. Design a legally permissible investigative strategy that could have been used between 1992 and 2015 to extract actionable information from Cox — without a confession, without physical evidence, and within the constraints of the Fifth Amendment.