Using the console and some quick mods that change the alignments of NPC's I have discovered
something inconsistent.

using player.getav karma after killing an NPC, Easy Pete for the purposes of this test, and
changing his alignment with mods, I got these results for my karma gain /loss

Easy Petes Alignment-------Karma gain/loss

Very Good.............................-100
Good.....................................-50
Neutral..................................... 0
Evil.........................................100
Very Evil...................................2


I would've thought that your karma gain from killing and
evil char would have been 50 and killing a very evil char 100 but
this makes no sense.

Could someone point me to a variable or something that determines how much karma you
get for different deeds?