I picked this up from one of my old posts at City Data Forum. I had forgotten about it.
Stanislau Shushkevich, who became the first President of Belarus after the collapse of the USSR, had been assigned to teach Russian to Oswald at the radio factory in Minsk (where my wife's sister and brother-in-law worked at the same time).
This is a long and pretty interesting interview from 2013 by Radio Free Europe. Shushkevich and the other instructor were, for some reason, under unbelievably strict orders as to what they could discuss with Oswald. Nevertheless, it sounds like they had a fairly informal and pleasant relationship. It sounds like he found Oswald a pretty dull and uninteresting/uninterested character.
When Norman Mailer visited Belarus and asked to see the KGB files, he (as President) asked the chairman of the KGB if he needed to be careful. The answer: "Absolutely not. Show him everything."
After the JFKA, he visited the Dallas area for other reasons. He's a CTer! "It is my absolute conviction that they found a passive, calm, compliant boy, and used him as the guilty one. As for the conclusions of the Warren Commission, I don't believe them one bit. I have studied them and I don't think [the assassination] was the work of my student."
https://www.rferl.org/a/interview-transcript-oswald-shushkevich-belarus-soviet/25172632.html