How to find who killed player ? (creator, victim)

example if player killed player and if player is in game i want to know who killed it and give him special stat.

I already tried linked leaderboard but its not helping me. Also i made script but its not working

Most weapons..

They have where.

When it touches another player, it'll create an object value in the touched player's humanoid

-- most leaderboard detects kills by finding the object value in the humanoid.

Thanks to super10099