For the generation born in the 1970s in the USSR it was not uncommon to have nearly all of the classmates to be imprisoned for various crimes either during the school years or shortly thereafter. This excellent answer by Sergey Zubkov, an author of some books on programming describes the situation quite well. I also have first-hand accounts, my relatives and other people I know also said that nearly all the class where they were studying was eventually imprisoned. The crimes were usually murders, robberies, making heavy injuries, beatings to death etc.
When I was studying in the 1980s/1990s the situation was quite similar. I speculate that this is not the case of other counties (I may be wrong, so correct me).
I wonder what share in the eventual breakup of the USSR belongs to this amount of crime. Was not it one of the major causes? I suspect that there is nothing similar in North Korea, and that country still has Communist government.