How do I make a chatted when someone says ;kill PLAYER, player dies?

I tried this:

function findPlayer(name)
    for _, player in ipairs(game.Players:GetPlayers()) do
        if player.Name:lower() == name:lower() then
            return player
        end
    end
end

game.Players.PlayerAdded:connect(function(plr)
	plr.Chatted:connect(function(msg)
		if msg:sub(1,5) == ";kill" then
			victim = findPlayer(msg:sub(7))
			if victim and victim.Character then
				victim.Character:BreakJoints()
			end
		end
	end)
end)

but I always get a error saying