former prosecutor melissa nelson. suspect, they were running that to ground. could it be this person? is it this person? >> reporter: amy lavin found herself looking around at corey's other friends and wondering, could it be one of them? >> everybody was an actual suspect. so that became a little bit scary to me. >> rteiller could have been right under your nose. >> yeah. >> reporter: tiffany zienta remembers just wanting to be helpful. like most of corey's friends, she met with the detectives. they want to talk to you, detectives? >> we all made a statement. >> reporter: well, they wanted to talk to you. >> absolutely. >> reporter: tiffany told the detectives she'd been with corey at the ritz bar wednesday night into the early-morning hours of thanksgiving. she said they left the bar at the same time, around 1:30 a.m. tiffany hitched a ride with another friend to go bar hopping. corey, she noted, got into her own car and headed home. later, tiffany said, she called corey's home phone. >> it was like 2:15. it was right after we left the them. carlyle says they

. >> reporter: melissa nelson, then an assistant prosecutor who joined the case, recalls the fear. >> neighbors were scared, people she worked with were alarmed. so, it was a very scary time for >> reporter: tiffany zienta, raised in jacksonville, beach, couldn't believe this had happened to someone she knew. >> i mean, they kept calling it the bloodiest crime scene in jacksonville beach in 25 years. that's not really comforting to feel or to hear. >> reporter: ashley burg was also frightened, for another reason. detectives thought her brother joe had been too vague about where he'd been in the hours surrounding corey's death. did he have a solid alibi? >> not really, no. >> reporter: what was he doing? apartment just hanging around. and he comes and goes. so we couldn't really establish a solid alibi at the time of the crime. >> reporter: their interest grew when they found a hair on a sock in corey's bedroom. the hair looked like it could have come from joe. >> i know we did a microscopic comparison. and that the microscopic comparison developed that likeness. >> reporter: the test