1987 "Dargnet" another example of an admission of guilt in plain sight.
>The trail leads Friday and Streebek to a come across a cult calling itself P.A.G.A.N. (People Against Goodness and Normalcy), and they focus on member Emil Muzz, who also works as Caesar's limousine driver. Under interrogation, Muzz reveals the time and place of a secret ceremony. Friday and Streebek sneak in, disguised as members, and witness a masked leader using several of the stolen items in a ritual leading up to a virgin sacrifice.
>Streebek gets a tip on the whereabouts of a load of chemicals stolen by P.A.G.A.N. that can be used to mass-produce a toxic gas.
https://en.wikipedia.org/wiki/Dragnet_(1987_film)