How to make Zombie Tag

I am trying to make a zombie tag type game were there is 1 permanent tagger in the beginning and as he goes about tagging other those people also become taggers. any one know how to code that?

to be more specific if they player dies by getting tagged their is the tagger that is not permanent will switch as well, so i need an player is attacked and a player takes fatal damage trigger? is it called trigger or script?