al ronnie gaskins hears roies was used to buy drugs for a local teendod oin. >> rep shea ane last twove their story. they picked up skylar at 11:00 p.m. ok joyride through the winding backroads of rural star tyr off before midnight. >> very to see the victim alive is looked at with great suspicion. in this case, the girl's story seemed relatively innocent. so police had no reason to believe both of them were lying. >> reporter: but for officer colebank it's the small, unspoken signs that make her suspicious. take me back to that moment where you go to speak to sheila the first time. >> just complete blank on emotions, and there was absolutely nothing. it was, like, iced o it made me uneasy. >> reporter: colebank's meetint drama star, also strikes her as odd. >> really nervous. >> reporter: has g what does she have to hide? >> their stories were verbatim the same. no one's story is exactly e same, unless it's rehearsed. and she's an actress, so she can memorize lines. i'm sure they had it wttdown so t to stick to it. everything in my gut was sheila. rael is scared to death. hiding, or

. >> reporter: for officer jessica colebank and corporal ronnie gaskins, the video is their best and only clue. what were you looking for? >> anything. >> trying to get pictures of the tires, the rims, but it's just too grainy. >> it just raised millions of other questions, of who did she go with and where did she go? >> reporter: next, what happened to skylar? everyone has their own theory. >> got drunk and fell and hit her head. >> somebody had followed her home. >> she'd met someone on the internet. >> somebody's just too scared to tell us what really happened. >> reporter: stay with us. ♪ ♪ [ male announcer ] if you can't stand the heat, get off the test track. get the mercedes-benz you've been burning for at the summer event, going on now at your authorized mercedes-benz dealer. but hurry, offers end july 31st. share your summer moments in your mercedes-benz with us. ♪ ♪ ♪ i think she tried to kill us. no, it's only 15 calories. with reddi wip, fruit never sounded more delicious, with 15 calories per serving and real cream, the sound of reddi wip is the sound of joy. i'm living