Sure. A Colombian serial killer named
Pedro López is free right now thanks to various legal bullshit. A good card-carrying communist can easily get away with the same amount of rape and murder in the Soviet Union by staying in the good graces of authorities and finding a way to get the murders blamed on "reactionaries", "counter-revolutionaries", "Trotskyists", whatever. It isn't much different than the case of
Paul Ogorzow in Nazi Germany, who was a member of the Nazi Party for many years and also an SA member and was able to get the authorities to blame Poles and Jews for his crimes.
Oskar Dirlewanger is another fantastic example of a Nazi serial killer who represents how powerful a serial killer can get thanks to being ideologically acceptable to powerful members of society. Though by Nazi ideology Dirlewanger was a degenerate alcoholic child molester and thus a very poor example of an Aryan, he managed to find some powerful protectors and thus was allowed to redirect his violent impulses onto Eastern Europe.
A case like Paul Ogorzow is a lot easier to have, thanks to the fact that as noted in this thread, Soviet serial killers were pretty similar in how they got people falsely accused and executed. A Dirlewanger-like case takes a lot of luck and knowing the right people. Of course, if you're a serial killer, and you have a protector high up in the Communist Party, and said protector ends up purged or demoted, you will end up caught before long, expelled from the Communist Party, and shot. And what happens post-Stalin is anyone's guess, but will also likely end up with you being shot.