True Detectives (04/05/91) | 1990
The third in a series of specials about professional and amateur detectives who have solved mysteries. In the summer of 1984, several residents of a houseboat community in San Francisco Bay heard a loud penetrating drone emanating from the waters that has yet to be identified. Two Seattle residents poisoned by cyanide-laced capsules spurs an investigation that reveals a murder plot. A man sentenced to 55 years in prison begins a letter-writing campaign to prove his innocence.