. >> reporter: mark moffat and ann taliaferro were those attorneys.t things they did was visit the scene of the crime. >> we went to the house, and we walked in and we think, a-ha. >> within moments of being in that home, we knew immediately that there was a huge problem. >> reporter: not a problem for them. more for the people who had put conrad truman away.>>coming up - an innocent man in jail for someone's mistake in math? >> i remember thinking, well, that's strange. that couldn't be right. >> we immediately started measuring. and we knew right away that there was a big problem. >> when "dateline" continues. nus ♪you've got the brawn♪ ♪i've got the brains♪ ♪let's make lots of♪ ♪uh uh uh♪ ♪oohhh there's a lot of opportunities♪ with allstate, drivers who switched saved over $700. saving is easy when you're in good hands. allstate click or call to switch today. feel the cool rush of claritin cool mint chewables. powerful 24-hour, non-drowsy, allergy relief plus an immediate cooling sensation for your throat. feel the clarity, and live claritin clear.