What Ever Happened to Mary Day?
This episode appears to contain dynamically inserted ads. Transcript timestamps may be approximate.
[Music] Marley Lee's Day was a girl that lived in seaside. [Music] In about 1981, she disappeared. What do you mean she disappeared? She disappeared off the face of the earth. [Music] I just knew something was wrong in the house. Mary Day's my sister. One day Mary was in California, and then she was gone. [Music] Laying about one night with Kathy, I asked her, you know, I was like, "What happened with Mary?" You know, and she was like, "Shh, don't say anything. We're not allowed to talk about Mary." [Music] When I was 18, I was like, "Now I can, you know, go and try to find her." [Music] It was a very hard case to deal with. Other than the family, nobody knew she was gone. Didn't seem to really concern them. She started running away. You turn around, she was gone. You turn around, she was gone. I've never seen a case like this. My mother told me that there were a lot of places in California that you could bury a body and they'd never be found. I started believing she was murdered. [Music] The dogs went into the backyard. We just had an indication from the cadaver dogs that there was. Their human remains there. And our guys started digging and my heart was pounding. We were looking for a little girl's body. And we found a little girl's shoe. [Music] [Music] William told me that he didn't kill Merry Day. But his wife told him that he was possessed that night. And that he had a demon inside of him. I've never heard anybody say that before. [Music] This is a crazy case. Mary disappeared. No trace of her for 22 years. And then what happens? And then I got a phone call. He told me, "Hey, Captain." He says, "You sitting down?" He said, "Gotta let you know."
Transcription truncated.
A 13-year-old girl vanishes in 1981. Detectives believe she was murdered. Years later, a woman appears and claims to be the missing girl. Is she an impostor? "48 Hours" correspondent Maureen Maher reports.