Looking for Answers

Hello all. I've been searching to answers about my parents and recently came across some information about my father. It turns out he is in the US FEDERAL BUREAU OF PRISONS FEDERAL INMATE REGISTRY.

I've tried searching records because, of course, I'm curious of the circumstances. The electronic records only go back to the 1980s, no further. Is there a way to access records from before the 1980s?

Thanks in advance.