American film directed by Billy Wilder and produced by the United States Department of War. Scope and content description at the National Archives Catalog [1] : Documentary: Highlights German concentration camps. Beginning and ending with the townspeople of Gardelegen, Germany, carrying crosses to a local barn containing 1,100 victims of the holocaust, shows victims of Auschwitz, Majdanck, Treblinka, Belsen, Buchenwald and other camps. Allied physicians examine sick and injured victims at Auschwitz; General Eisenhower and other officers visit Ohrdruf; Archbishop of Canterbury and other church
You can stream Death Mills (1945) (1945) free and legally on alltube, via the Internet Archive.
Yes — it is in the public domain and can be watched and shared freely.