of the missing pharmaceutical representative landed on the desks of sergeant mia and detective greg jacobsonright away, scanned nailah's phone records and found something alarming. just after 10:00 p.m., the night nailah vanished, her cell phone made three calls to 911. >> chicago emergency. >> no voice, no struggles could be heard. no background noise with the exception of some light music in the background. >> i guess it could be kind of eerie to hear that, huh? >> yes, it is. is the person physically unable to complete the conversation and just able to dial a 911. >> so the investigators set about talking to just about everybody nailah knew. >> there was interviews completed through doctors she had visited to try to retrace her steps and people she had encountered. >> a lot of people. >> of course. anyone we knew who had a relationship with her. >> maybe leah's pr campaign helped because -- >> we had some anonymous tips, people saying that they saw her at this location. >> but not a single one of them led to nailah. by now the detectives believed they were dealing with a serious crime, an

. >> the case of missing pharmaceutical representative landed on the desk of greg jacobson who scanned. the night niela vanished her cell phone made three calls to 911. >> no voice. no struggles could be heard. no background noise with the exception of light music in the background. >> it could be kind of eerie. >> yes, it is. >> a person just able to dial a 911. >> the investigator started to talking to just about everybody she knew. >> a lot of you were talking. >> of course, anyone we knew had a relationship with her. >> maybe her pr campaign helped because -- >> we had some anonymous tips, people saying they saw her at this location. >> but not a single one lead to niela. now they believed she was dealing with a serious crime. >> she is missing. technically there hasn't been a crime committed. >> i knew the boyfriend she was in wisconsin with, they were all interviewed. >> that boyfriend from wisconsin had come to chicago, was helping with the search and soon was perhaps the sub jek ject of it. >> they came to you. >> yes. >> and now to police, a perfectly obvious person of interes