In an episode of "Adam 12" called "the Radical", Reed and Malloy bust a ring of thieves who use stolen trucks to move their loot. This leads them to a revolutionary named Robin Saydo. Reed and Malloy then get Saydo before he can do anything with a cache of hidden guns. This epidode of the "D.A." shows Ryan's efforts to convict Saydo. The case centers around wheteher Reed and Malloy had probable cause to enter the warehouse where they caught Saydo with his weapons. The one witness who can make this case is sympathetic to Saydo and refuses to testify agianst him.
Ryan tries to convice the witness that Saydo isn't just someone protesting unjust government actions. He represents a threat to the public.
In the end the witness is called to the stand and he does testify against Saydo.