. >> reporter: linda talking about erin goldburg a quiet, but playful animation grad student at academyart university. >> that's what she wanted to do with her animation. smile her whole life. >> reporter: what happened to the 24-year-old back in june 2015 is still a mystery. she took a cab to the marin headlands on that blustery night. she brought her camera along after researching on the internet the national park services monthly guided full moon walk to the point benita lighthouse. >> erin loved the full moon. she loved the golden gate bridge. what a great opportunity to go and take photos and be in a safe environment because it's a national park event. >> reporter: still, the cab driver told authorities in a taped interview that he was concerned about leaving her there. >> it just didn't seem right to me, but i didn't ask any questions. or anything like that. but to be out there once it got dark, just didn't seem right. >> reporter: she checked her voicemail at 8:00 p.m. 20 minutes after the walk began. at 9:18 p.m., she texted good night mama llama to her mother. no one heard from