Was Guilty Conscience the made for TV movie with Blythe Danner and Anthony Hopkins originally a play?

You're right to be curious! "Guilty Conscience" (1983) was indeed based on a play, but it wasn't a play originally. It was a British television play titled "The Guilty" that was first broadcast in 1975.

It was written by Reginald Rose, who also wrote the famous "12 Angry Men" play and later adapted it into a classic movie.

Blythe Danner and Anthony Hopkins starred in the 1983 American television film adaptation of this story, which was more of a remake than a direct adaptation.