According to Crime Online, Karlie’s step-mother, Melissa, told investigators that the night before Karlie’s disappearance, she picked her up at around 8:30 p.m. and that Karlie had told her she’d smoked marijuana and was feeling “paranoid.” To her stepmother, Karlie seemed “disoriented.” 

Stories of the Unsolved reports that Karlie’s behavior after Gusé picked her up that night was highly erratic — the teen was paranoid that someone was going to kill her or that she would die. She was particularly concerned about being traced on her cell phone. This leads some to believe Karlie Gusé was on something other than marijuana that night and possibly still high when she left the house. 

After some time, Karlie calmed down and Gusé slept next to her, per Crime Online. Melissa woke up around 5:30 a.m. and saw Karlie lying in bed with her eyes open, then drifted off again until 7:15 or 7:30 a.m. When she awoke, she says, Karlie was gone.

Karlie’s father, Zachary Gusé told the FBI he has two theories: He said he believes that Karlie either walked so far into the desert that she died out there, or she was abducted as she was walking down the road, per an interview on YouTube.

In another FBI interview posted to YouTube, Bishop Union High School Principal David Kalk said that at first, it felt like Karlie would turn up, but after multiple searches provided no clues (and with so much time passing), he thinks in the backs of people’s minds they’re “resigned to the fact that we may never see Karlie again.”