Conversation so far:
What was Aleksandr Solzhenitsyn's role during World War II?
During the war, Aleksandr Solzhenitsyn served as the commander of a sound-ranging battery in the Red Army, was involved in major action at the front, and was twice decorated.
Did Aleksandr Solzhenitsyn win any awards or recognition?
Aleksandr Solzhenitsyn was awarded the Order of the Red Star on 8 July 1944 for sound-ranging two German artillery batteries and adjusting counterbattery fire onto them.
Where did Aleksandr Solzhenitsyn serve during  World War II?
While serving as an artillery officer in East Prussia, Aleksandr Solzhenitsyn witnessed war crimes against local German civilians by Soviet military personnel.
Did anything notable happen to Aleksandr Solzhenitsyn during his service?
Aleksandr Solzhenitsyn witnessed war crimes against local German civilians by Soviet military personnel.

Question: What kind of actions did he witness in these crimes?
Self-contained rewrite: What kind of actions did Aleksandr Solzhenitsyn witness in these crimes?