An exceptional movie “Katyn” given to my husband when he was in Poland for work. Have watched it many times. Lots of great acting and history and old footage. https://www.imdb.com/title/tt0879843/?ref_=fn_al_tt_1
EVERYONE should watch the superb and poignant Polish film, Katyn, which is free on YouTube, somewhere, with English subtitles.
Really, greally great film.
Indeed. Highly recommended.
Another film regarding how truly brutal the Soviets were is the Chekist.