How do you play cops and robbers?

how you play cops and robbers is there is a jail were there is a person body guarding so they won't escape and if they escape well you have to try to find them again then get in even groups and there are two (2) groups then you count to thirty (30) seconds and then you chase the robbers when you get them you put them in the jail with body guard or guard keeps them from getting out then when you get all the robbers cops you start all over the same routin