Graham has a long history of fraud and other crimes. When she was arrested, police found that she has used 47 aliases and was carrying 10 different driver's licenses. That history was somehow missed by a DCF background check.

"Her whole life was a scam. We still don't know who she was, even after she was fingerprinted," said former Miami-Dade detective Gregory Scott, who retired in 2004 and was an early investigator in Rilya's case.

Pamela Graham, who remains charged with child neglect, has been cooperating with prosecutors and is expected to testify. In sworn statements, she has insisted she does not know what happened to Rilya.

Ultimately, according to Nova law professor Jarvis, the jury will have to be convinced that there's no other explanation for Rilya's death in order to convict Graham.

"Other than foul play, is there any reasonable explanation for the missing person's disappearance?" he said. "Assuming the answer is no, is there any reasonable doubt that someone other than the accused is the perpetrator?"