Bad Ronald True Story
here you go. Not the exact story, but close enough.
http://www.necn.com/news/national-international/NATL-Boy-Missing-for-4-Years-Found-in-False-Wall-Police-284213911.html
That is amazing, I had just read that story a few minutes ago and instantly thought of this movie, which I haven't seen since I was a kid in the 70s. I had no idea what it was called so I just googled for "fake wall murder movie 1970s" and found it. I've thought of this movie from time to time and wondered what its name was. It completely freaked me out as a kid; I wonder if it would still chill me today or if it would just seem campy. The title alone is a big let-down; it sounds like a Troma film.
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