How to get registration paper for motorcycle

Hi guys.  I have a question.  A while ago I bought a motorcycle  off a guy and he said he'd send me the motorcycle's papers.  It is now about a year later and still haven't received anything.  I have also discovered that he has left the country.  So, no papers for me.  Is there any way I can get around this and get plates for my bike?  I don't want to drive illegally.   Any help in this regard would be great.  Thanks!!