Vanilla base game. No mods or CC of any kind. Pretty simply, I have a sim with the Public Enemy aspiration and he needs to witness the death of a sim. I picked out his housemate as the victim and have tried everything I can think of to get the dang woman to get enraged, but it's just not working. Must've done a string of nearly 30 evil/mean interactions. At one point, she had three angry moodlets from being voodoo'd, riled up, and having an aggravating conversation. I've had them fight, prank, insult, etc. She won't budge past Very Angry. I even tried the add buff cheat, but it didn't work at all =/ . I didn't want to go the boring (and long) route of starving/drowning her, as I've never had a death by emotion yet. Any suggestions on what might be preventing her from getting Enraged?

I'm not sure why your sim can't get enraged, but you might want to try even more ways to get angry to add on.
There actually are other emotions that can kill your sim! Laughing to death is a very real possibility, and I believe too extreme of ANY emotion can kill your sim too! Elders can also die from woohooing.
It takes longer, but you could always turn your lifespan to short and get an elder sim.
Hope this helps!