>> the girls called security, describing a two-tone van driven by a man with mutton chopped side burns. officers spotted the van and talked to the driver, a man named larry hall. he said he was looking for a friend's address but the address he gave didn't exist. so officers let hall go. september 20th, 1993. six months after trisha's disappearance, now 15-year-old jessica roach goes missing in georgetown, illinois. investigator gary miller got the call. >> we all knew that we had something really bad here. we had an abduction. >> jessica's badly decompose body was found in an indiana cornfield weeks later. but then, like trisha's jessica's case went cold. >> there's a lot of times you wonder whether you'll ever solve it but you know you'll keep going and check everything out and recheck everything. >> for over a year, miller scoured local police reports and then, a break. a vehicle reported in a county nearby. the owner? larry hall. >> he had been involved in stopping some girls. those girls were scared.