officer jessica colebank pours through her facebook and twitter posts.s sets off alarms. >> you could tell she was mad at someone. >> in the weeks before she vanished skylar had posted angry messages, there's just something about you i can't [ bleep ] stand. people can be so mean for absolutely no reason. hope you don't expect me to give a [ bleep ] anymore. #bye. and the final tweet she wrote, sent 10:48 p.m. the night she disappeared. you doing [ bleep ] like that is why i will never completely trust you. >> she didn't trust someone. that was the issue and perhaps the most suspicious posting the strange game among best friends. sheila asks rachel and skylar how they prefer to die. >> would you guys rather suffocate or get shot. >> shot. shot have drowning or suffocating. >> suffocating. >> it's almost the same thing. >> i know but it's not. >> and when police reveal their cell phone messages they notice a curious absence. >> there was no mention of skylar whatsoever. it's as if she just erased it from her mind forever. >> skylar has been missing for mo