right, that's why I said "theoretically"
the entire notion is pretty idiotic, though
why would you bother "making an appearance" of killing somebody and serve the sentence, all just so you could kill someone once you get out?
how do you achieve such a thing without disposing of said someone? wouldn't that pull other criminal acts, such as conspiracy, or something?
does that make any sense whatsoever?
There was a movie...

with Al Pacino, where he made digital on-screen actress that everybody believed was real. He decided to get rid of her and threw all tapes in trunk and trunk in the sea. He was arrested under suspicion of murder and he couldn't prove he didn't do it...
But my idea came from a sci-fi story I read long time ago about "earning" a murder.
Two guys get to work in some mines on alien planet for 12 years. The catch is convicts in these mines have very low survivability rate, so when you serve 12 years and survive you get one free kill: you can kill anyone you want.
The best part is they get TV coverage and radio is always asking - "Who are they going to kill?" - like it's world series or something.
First guy wanted to kill his wife, but when he got out he found out that she died in an accident one month earlier (probably with a smile on her face, because she tricked him into serving sentence or nothing

).
Second guy had a target in mind - someone who he thought betrayed him. However during the story he started to get calls from a bunch of individuals close to him, confessing how they conned him, etc. asking not to kill them, so he called that guy (his intended target) and said to him that he wanted to kill him for betrayal but now he sees that he was the most honest guy in the bunch.
Anyway, story ends with these ex-convicts sitting in an second floor restaurant and then throwing a couple of grenades randomly out the window killing couple of pedestrians on the street. When police arrives they just introduce themselves and ask the officer: "Where do I need to sign off?"