If the person has been imprisoned repeatedly he might be called a gaol-bird:-


  a criminal who has been jailed repeatedly


Edit Green's Dictionary of Slang has it:-


  
  A prisoner
  A former prison inmate
  


What would you call a former criminal who has been released from prison?
I've recently taking up making fudge for family and friends.  However, my cutting technique lacks a desirable smooth uniform piece. How can I cut equal smooth cuts? 
