I need to witness the death of a sim.

Done!(Finally) So I befriended some townie, actually became quite good friends, she moved in, trapped her in a pool(build a fence) and she died. What I did extra was bought a voodoo doll, bind it to the victim and used the poke interaction. I also gave the sim who had to witness the death the Observant trait(where you can get it in the reward section)and made the victim swim laps until I couldn't use the interaction anymore. So when the victim died (poor her) my actual sim was in the kitchen cooking, I stopped the cooking interaction and brought her in the garden where the trapped sim was. I notice then I'm not sure what's it call but the circle where what's your sim is doing, it said something with witness and voila that's how I did it.

This took me four attempts
Good luck my simmers ;)