Converting an Anti-Team kill script?

I would like to know if it is possible to change this script into a different script that prevents users from actually hurting/killing each other. This script allows friendly fire but kills the person who actually caused it too.

print("TK script loaded.")

function onHumanoidDied(humanoid, player)
        local killer = getKillerOfHumanoidIfStillInGame(humanoid)
        if (killer ~= nil) then
        handleTKs(player, killer)
        end
end

function onPlayerRespawn(property, player)
    -- need to connect to new humanoid

    if property == "Character" and player.Character ~= nil then
        local humanoid = player.Character.Humanoid
            local p = player
            local h = humanoid
            humanoid.Died:connect(function() onHumanoidDied(h, p) end )
    end
end

function getKillerOfHumanoidIfStillInGame(humanoid)
    -- returns the player object that killed this humanoid
    -- returns nil if the killer is no longer in the game

    -- check for kill tag on humanoid - may be more than one - todo: deal with this
    local tag = humanoid:findFirstChild("creator")

    -- find player with name on tag
    if tag ~= nil then
        local killer = tag.Value
        if killer.Parent ~= nil then
            return killer
        end
    end

    return nil
end

function handleTKs(player, killer)
    if (killer.TeamColor == player.TeamColor) then
    killer.Character.Humanoid.Health = 0
    end
end

function onPlayerEntered(newPlayer)
        while true do
            if newPlayer.Character ~= nil then break end
            wait(3)
        end

        local humanoid = newPlayer.Character.Humanoid

        humanoid.Died:connect(function() onHumanoidDied(humanoid, newPlayer) end )
        newPlayer.Changed:connect(function(property) onPlayerRespawn(property, newPlayer) end )
end

game.Players.ChildAdded:connect(onPlayerEntered)