maribel was leading by example, finishing up her degree in criminal justice at cal state fullerton.iselle was following in her strong footsteps. >> and she was dropping off money at my house because i had gotten good grades. and she had just got her hair done, dyed and styled for her graduation. >> reporter: she looked great? >> yeah. >> reporter: and she was happy? >> yeah, she was. >> reporter: and that's why it made no sense when, just days later, maribel ramos -- soldier, student, loving aunt -- simply disappeared. >>> what had happened to maribel ramos? when we come back -- >> i'm freaking out! her door is open, her lights are on, her bed's undone. everything was horrible, and i felt it. >> the mystery was about to deepen. >> nobody had heard from her? >> nobody. i'm telling you i heard something... oh! (awkwardly laughs) get out. enough's enough! d-con baits are fomulated to kill in one feeding. guaranteed. before the first sneeze, help whenprotect with a spray. ead. before the first tissue, help defend with a wipe. and help prevent with lysol. to get ten times more protection

. >> there was a person at cal state fullerton that was in the veteran's association with her that hadiven her a bad feeling. he may have wanted to pursue some sort of dating relationship. >> reporter: but it gave her a bad feeling how? >> she wasn't interested in him, and she didn't give him any attention, yet he didn't go away. >> reporter: so he made her feel uncomfortable? >> correct. >> reporter: and by now, detective ramirez had learned something else. just a little over a week before she vanished, maribel ramos had called 911. >> hi, orange police. >> hi, it's not an emergency, but i just -- is there recording? >> is there a what? >> is this conversation recording? >> yes, every conversation is recorded. >> reporter: maribel wanted it on the record. she wanted police to know that she was very afraid of someone. >> i'm just like calling so that you guys know that if something happens, i did it because i was trying to defend myself. >> reporter: she might have been afraid, but this army-strong woman who'd always taken care of herself feared she might be the one putting the hurt on