murder should be repaid with losing your job
not like prison time or anything
but it's different than being a frycook or a secretary - a policemen is given to right to kill under dire circumstances. citizens are not allowed to kill under dire circumstances unless in self defense, and even those laws are shaky(remember zimmerman?)
he had the right to kill, he misused it, and now he's a citizen again. jail is to teach people the error of their ways - he already learned it the hard way, and he's going to be remembered forever for what he did. jail would do nothing for him or society.
i don't support what he did in the slightest, but vengeance is not what we should focus try people on. besides, he'd get his throat slit in two days if he got locked up.