Look at what Aleksandr Solzhenitsyn wrote about Joseph Stalin’s use of common criminals against his political opponents:
And Stalin was always partial to the thieves–after all, who robbed the banks for him? Back in 1901 his comrades in the Party and in prison accused him of using common criminals against his political enemies. From the twenties on, the obliging term “social ally” came to be widely used. That was Makarenko’s contention too: these could be reformed. According to Makarenko*, the origin of crime lay solely in the “counterrevolutionary underground.” (Those were the ones who couldn’t be reformed–engineers, priests, SR’s, Mensheviks.)
And why shouldn’t they steal, if there was no one to put a stop to it? Three or four brazen thieves working hand in glove could lord it over several dozen frightened and cowed pseudo politicals.
With the approval of the administration. On the basis of the Progressive Doctrine.
The Gulag Archipelago, Volume 1, pp 505-506
*Per the glossary in Volume 1 of The Gulag Archipelago, Anton Semyonovich Makarenko “organized rehabilitation colonies for juvenile delinquents.”