craig melvin: gracie ramirez was melissa's sister-in-law. ciara ramirez: we were like sisters. we were super close to each other. craig melvin: melissa's mom likes to remember her daughter as she was. [speaking spanish] translator: she got good grades. i never struggled with her. i never had problems with her. craig melvin: that was before her early teens, before a bipolar diagnosis that went untreated. gracie says melissa never let on to her family that she turned to drugs and then sex work. she really kept her life split in two, didn't she? she was very private to her life. craig melvin: still, when melissa would leave for days at a time, her family knew it couldn't be for anything good. ciara ramirez: so she would come visit me. i would beg her to stay with me. i would feed her. i would give her everything she needed. but she just insisted that she needed to head out. but she wouldn't say where. no, she would never tell me where, nor her-- her brother. she wouldn't tell anybody. craig melvin: now, melissa had met a brutal end. priscilla villarreal: a female was found deceased