Not sure if the Columbo series did it deliberately but after watching the Great Santini:
… I read this below it:
Jack Cassidy was great in all of his appearances on Columbo(3). Sadly he died in a fire 7 months after this episode. [Mike Wall]
… then went to the cast and crew:
… and quickly found:
Now in that show, the character of the killer is an indifferent, cold, strange man with a glib tongue, too clever for his own good, always setting things on fire – remember that this show came before his death in a fire, natch.
It makes great play in the show of his being [spoiler] a Nazi war criminal [end spoiler] and of his German accent. But in real life, he had that German element too.
Then I looked at the “daughter” in the show who helped him with his stunts:
… then read more widely on her and up came all her “personal issues” all her life.
I’ll not quote extensively, in an attempt to keep the post short, but both were very weird people playing very weird people in the show. Interesting.