Why wont this admin script work? [closed]

It does everything but kill the player. I want it so that you don't need to type the full name of a player, but obviously I have failed.

players = game:GetService("Players")
admins = {["Player"] = true ; }

players.PlayerAdded:connect(function(newPlayer)
    if admins[newPlayer.Name] then
        newPlayer.Chatted:connect(function(msg, speaker)
            if string.sub (msg, 1, 6) == ":kill " then
                for _,v in pairs (players:GetPlayers()) do
                    if v.Name:match(string.lower(msg, 6, string.len(msg))) then
                        v.Character.Humanoid.Health = 0
                    end
                end
            end
        end)
    end
end)