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 decomposed 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.