Honeychile, I am sorry for your loss.  That's messed up and I hope karma comes back and kicks the sumbitch's ass! 
Would I marry someone just for citizenship?  HELL NO!  Mr. 1228's first wife married him for a meal ticket, FORGED his name on the immigration docs to get her parents over here.  He learned that lesson.
I did marry someone from another country, but we waited until after we got married to file paperwork.