It was Frederick Wiseman's 1966 documentary film "Titicut Follies," a harrowing view of life in an asylum in Massachusetts.
I am wondering about the impact of modern media on the shooter. Could sitting at home and watching beheading videos all day make you callous enough to shoot babies at point blank range?
I remember reading a review of Titicut Follies at that time. Never saw it though. It was a rough review.
There is one response to your speculation “No one has heard of the latter while millions have heard of the former.