There were two–and maybe three–different people. In both the 1950s and 1960s versions, George Fenneman intoned “The story you are about to see is true, etc.”
Art Gilmore (who was one of the pool of actors Webb employed to portray the captain-of-the-week) did the voice-over in the 1950s version announcing the results of the results of the trial.
However, the voice-over for the trial results in the 1960s version does not at all sound like Gilmore. Since he frequently played the boss, it’s easy to compare. If he is still the announcer, he is using a different voice.
So. . . .
Any ideas on who the mystery announcer in the 1960s version was? It sounds sorta like authoritative-white-lab-coat-wearing-actor-at-large Whit Bissell, but I don’t think it is.
(I had already posted this question on the IMDB board, and the only response offered Art Gilmore as the mystery voice.)