>> on top of the video surveillance, the phone records, rachel's statements at that point we felt we had confidence to have probable cause to make the arrest. >> now authorities told skylar's parents the whole story. their daughter's two best friends had killed her. >> i think about it every day. i think about the misery my child must have been through. and i'm helpless. i can't help her. she's calling out "help me, why, why, why." >> animals got her. they didn't even care. >> no. they just threw her out like a bag of trash. >> on may 1st, 2013, in exchange for her cooperation with police, rachel shoaf pleaded guilty to second-degree murder. within minutes, gaskins raced across morgantown, his heart pounding. >> obviously we were going lights and sirens because we had a murder warrant to serve. >> sheila was arrested and charged with first-degree murder