By my recollection, about the early 1960's. About the time all networks added a commentary with the "news".
Yeah. I think around the time Kennedy was assassinated.
They saw they could draw big crowds for many hours with millions watching. The space program was also “must watch” live TV.
Things deteriorated from that. To wit:
The Watergate hearings
Three Mile Island
Iranian hostages
Iran “Contra-gate” hearings
From an interesting newspaper movie, Deadline USA.
I came over the river Jordan from a weekly scandal sheet and asked old John Garrison for a job.
Are you a journalist or a reporter he said.
What's the difference I said.
He answered. A journalist makes itself a hero of the story while the Reporter merely becomes the witness.