Do I fire the 3rd bullet on the river or check it down with my 2 pair?

the opponent was moved to my table about 1/2 hour prior, played only 1 hand; so very little read on him. I assume he has a spec. hand by limping; he calls all of my raises and then checks again to me on the river; I cant play him for aa or aj or jj as he didnt raise the pot preflop; and I have a blocker for the 44; I do not see him hitting a straight and no flush; so I moved all in with my 2 pair; but he has to be calling with something; so in this tournament setting should I check back the river? (he had 44 and I was knocked out). Thanks, Tim