From an earlier answer of mine

Although policing and sentencing practices varied over time, the Soviet state tended to approach crime from a sociologically-defined perspective in which criminal acts reflected larger problems within a social organization. This added a potential gloss to criminal acts as they were transgressions against the alleged Soviet utopia. This interpretation of crime was especially acute during Stalinism when Soviet police saw incidents of disorder and petty crime as the result the existence of asocial undesirables. So an incident of petty crime like theft could sometimes get enfolded into a larger concerns like youth hooliganism if the perpetrator was young, or worse, wrecking if the accused was from the wrong class background or insuted the wrong person. This often meant much harsher penalties and jail sentences because the accused's acts could be interpreted in the courts as against the social order.

Up to 1989, a trial in a criminal case would have been with a single judge aided by two or more people's assessors. Decisions were done by a majority vote. Judges within the Soviet legal system were nominated by the local Communist Party, placed on a ballot (often being the only one) and voted in for five year terms. Lay assessors came from the local jurisdiction's populace and vetted by the Party for legal competence and political reliability. Assessors would be nominated and then put on a duty roster. The people's assessors were able to read the pretrial investigative reports, question witnesses, and decide not only guilt, but also contributed to the scale of the sentence.

One of the byproducts of this trial system was that the judges were highly dependent upon the state both in selection and their future careers, so it was not a truly independent judiciary despite Soviet legal and constitutional pretenses. A Soviet judge had to be able to read the political winds of the current political situation when it came down to verdicts and sentencing. The immediate post-Stalin era was especially confusing because Khrushchev's denunciation of Stalin did not lead to a wholesale political purges, which is what hitherto had characterized Soviet political transitions.The people's assessors gained a reputation of being "nodders" that deferred their opinions towards the professional judges.

One of the imperatives for someone accused of a petty crime like theft was to try and individualize and particularize the criminal act. This made it essential for defendants to argue that their case was a lichnoe delo (private matter) and not obshchestvennoe delo (a matter of public concern). Therefore it was crucial for a defendant to establish his motive clearly before the court. This made a good lawyer essential for a defendant. For ordinary criminal cases (i.e. not higher level treason or crimes involving national security), a Soviet citizen had a right to a public defender, although they could not consult with their clients until after the state had ended its investigation. The Soviet state capped the fees defense attorneys could charge, so good lawyers operated with a series of under the table payments. If a defendant or their family lacked resources, then their potential pool of defense attorneys shrank accordingly.

One of the legacies of Stalinist police methods is that it also imparted a degree of hostility towards habitual offenders. The Soviet legal system held it as orthodoxy that every criminal (save traitors against the state) was capable of reform by the state. Even though this was legally enshrined, the flip side of the coin is that if one is a repeat offender, then one did not accept the helping hand of the state and thus deserves greater punishment. One Moscow lawyer during the Thaw was censured for pushing this line too publicly by saying "there are pathological people that are completely unreformable and such people should be given the most severe punishments." However, this attitude was common among Soviet law enforcement.

For crimes like theft, another important variable would be what was stolen and where. Stealing state-owned property was a more serious crime in many respects than the theft of individual property. One absurd case was of a man charged with destruction of state property when he broke into his apartment when he lost his keys, with the lock and door being property of the state. Theft or destruction of state property could have added the ambiguous moniker of "anti-social behavior" to the charge. An example of an extreme case in which this jurisprudence could be applied was in Alma-Ata where two men got a ten day jail sentence for picking roadside flowers for their girlfriends (theft coupled with vandalism made this innocuous act anti-social).

The conditions in Soviet jails were not comfortable and often quite underfunded. The latter feature was not that uncommon for Soviet infrastructure. In theory, the Soviet prison system was predicated upon reforming the criminal, but in practice the Soviet law enforcement officials saw crime as an example of social deviance, especially for repeat offenders. So while some prison officials were serious about reform, there were a great many that just gave it lip service.

One of the common features of Soviet prisons that was consistent throughout the various historical periods was the state was a firm believer in the efficacy of corrective labor. There were few dedicated programs for rehabilitation as the Soviet state believed work was rehabilitation. The type of prisons within the USSR reflected this sentiment. There were roughly three types of prisons within the USSR for ordinary criminals (crimes the state deemed political were run by the KGB): closed prisons (tuir'ma), that were more like conventional prisons, labor colonies (Ispravitel'no-trudovaia koloniia) which were sometimes called lager and hewed towards the stereotype of forced labor camps, and colony settlements (Koloniia-poseleniia) which had greater freedoms for convicts (they could wear their own clothing, travel within the colony, and live with their family if the colony authorities granted permission). Soviet closed prisons were notorious for their unhygienic facilities, meager food rations, and arbitrary abuse by the guards. The various labor colonies often entailed relocation and thus exemplified the shell-game the Soviets sometimes played with social problems. By relocating troublemakers away into the vast Soviet hinterland, they could pretend that crime did not exist. Even though crime rates were much lower than in the West, the existence of crime in the USSR was antithetical to the state's pretenses that crime was a strictly capitalist social problem. Individual criminals could exist in this formulation, but not criminality or crime as a social phenomena. There was a similiar reaction to homelessness- it was illegal to be homeless in the USSR, so local law enforcement shunted vagrants away from where they were caught.

Thus even though the various Soviet constitutions declared the judiciary were independent and subordinate only to the law, the execution of justice was highly politicized, even for "run-of-the-mill-crimes." Although the post-Stalin era of the Thaw tried to enact a more liberalized legal system, Soviet justice could be arbitrary and capricious.

Sources

Eaton, Katherine Bliss. Daily Life in the Soviet Union. Westport, Conn: Greenwood Press, 2004.

Feldbrugge, F. J. M., Gerard Pieter van den Berg, and William B. Simons. Encyclopedia of Soviet Law. Dordrecht: M. Nijhoff Publishers, 1985.

Hagenloh, Paul. Stalin's Police: Public Order and Mass Repression in the USSR, 1926-1941. Washington, D.C.: Woodrow Wilson Center Press, 2009.

Helsinki Watch (Organization : U.S.), Robert Kushen, Herman Schwartz, and Abner J. Mikva. Prison Conditions in the Soviet Union: A Report of Facilities in Russia and Azerbaidzhan. New York: Human Rights Watch, 1991.

LaPierre, Brian. Hooligans in Khrushchev's Russia: Defining, Policing, and Producing Deviance During the Thaw. Madison: University of Wisconsin Press, 2012.