Sounds true. They did not just killed people, but forced them to self confess to incredible crimes, they have never committed.
Unlike most other dictators, they forced people to praise and thank them for the abuse. There were no neutrals allowed.
E.g. Franco in Spain was ruthless and took care about all opposition. If you said something and he got wind of it, you were punished, ruthlessly! But if you just mind your own, you could live OK there.
The commies demanded a full verbal alliance. You have to go to parades, express support, thank party for all the goods, denounce traitors. No neutrality allowed.
Until the last years, when it was obvious to everybody that they are a dismal failure. They were still punishing dissent (see previous posts), but became more tolerant to the neutrals.
In their own words, they lost the revolutionary zeal.
The story of Milada Horakova, immediately comes to mind. They held a show trial and basically she refused to confess to the made up charges. They eventually executed her. There was a good movie about her on Netflix called "Milada", I highly recommend it.