for investigators, centering around doug stewart and some mystery man in virginia. >> these points all represent cellphone towers. >> reporter: back in michigan, detective criger was checking doug's cell phone records, hoping to come up with some answers. >> reporter: what jumped out at you? anything obvious? >> the biggest part was three or four days just prior to venus' disappearance, there were numerous calls, between 7 and 15 calls per day to and from doug, from one particular number. >> reporter: a constant phone-mate but the detectives also noticed a gap. the day before venus went missing, the cell phone was turned off. it didn't go back on until the next night. >> and then, all of a sudden, the calls start coming back to and from this same number. >> reporter: so the question becomes, who's at the other end of this phone call, huh? >> right. >> reporter: it was quick work finding out who the phone pal was. the calls were traced to the small town of bear, delaware to a young man named ricky spencer. ricky was a college kid, living in suburbia with his parents.