Are There More Victims of Ariel Castro?

Rescued kidnap victim Michelle Knight reportedly told police there was another victim in Ariel Casto's house years ago. INSIDE EDITION spoke to a woman who's still searching for her sister who went missing in the area.

Tonia Adkins is desperately searching for her missing sister, and she came to Ariel Castro's house of horrors because she believes that her sister may have been another one of his victims.

Christina Adkins disappeared 18 years ago. She was last seen just a half-mile from Castro's house on Seymour Avenue.

Adkins told INSIDE EDITION, "Christina was going from a neighbor's house to her boyfriend's house, which was only two houses away, and in between the two houses she disappeared."

Christina was 17 when she vanished. Her sister and her mom can't help but wonder if she ended up in Castro's house of horrors.

Looking at Ariel Castro's house, Tonia said, "It's hard to believe that at this house, so much horror and so much terror has gone on."

Victim Michelle Knight, who was rescued along with Amanda Berry and Gina DeJesus after 11 years of captivity, reportedly told police that there was another woman there when she was kidnapped in 2002. But one morning she woke up and the woman was gone. The letters - R.I.P.  for Rest In Peace, along with a woman's name were scrawled on the basement wall.

"I hope and pray that it's not my sister's name on that wall," said Tonia.

And there's another missing Cleveland girl whose case is receiving renewed attention since the arrest of Ariel Castro.

Ashley Summers was 14 when she vanished in 2007, just blocks from where Amanda Berry and Gina DeJesus were abducted.

On Oprah Winfrey's talk show four years ago an FBI special agent linked Ashley's disappearance to Amanda's and Gina's, saying, "This happened within half a mile of this other area of where Amanda Berry and Gina DeJesus disappeared from."