Erica Parsons, 15, was reported missing by her older brother on July 30, 2013, but he says the last time he saw her was on November 19, 2011. The 20-year-old told authorities that he doesn’t think his sister is missing – he believes his parents killed her.

WATCH: Erica Parsons’ Adoptive Mother Describes What She Says Happened The Last Day She Saw Her

Erica’s adoptive parents, Sandy and Casey, say Erica isn’t missing — she went to live with her biological paternal grandmother, “Nan,” in December 2011. They say she was supposed to stay for three weeks and return home, but she continues to live with her grandma.

WATCH: Why Erica Parsons’ Adoptive Parents Say They Aren’t Concerned That They Haven’t Heard From Their Daughter

In the video above, Sandy and Casey offer a message to Nan.

WATCH: Parents Of Missing Erica Parsons Agree To Take Polygraph Exams – See The Results

Police say there is no “Nan,” and Erica’s biological grandmother died five years ago. They say Erica’s parents are being uncooperative and that the information they’ve provided isn’t true. Watch more from this show here.