"At heart here is people who didn't want to be bothered by the system. It is beyond a tragic situation," Lawrence said of both cases. "You still need compassion, decency and common sense."
In Graham's case, the star prosecution witness will be Robin Lunceford, a career criminal who had been sentenced to life behind bars before revealing Graham's purported confession. Lunceford's sentence was reduced to 10 years after she came forward. She is now scheduled for release in March 2014.
Lunceford told detectives that Graham, whom she had befriended, was talking to her from an adjacent cell and "broke down, said she couldn't take it anymore, that she had killed the little girl and buried her near her home." Lunceford said Graham told her she smothered Rilya with a pillow because the girl insisted on wearing a Cleopatra costume for Halloween rather than going as an angel. A second inmate also will testify that Graham confessed to the killing in another conversation.
Other prosecution evidence centers on allegations of abuse, including claims that Graham tied Rilya to a bed or locked her in a small laundry room as punishment for misbehavior. There were also reports by friends and acquaintances that the girl was frequently seen with bruises and scratches.
Michael Grieco, a former Miami-Dade County prosecutor now in private practice, said that testimony may help build a circumstantial case against Graham.
"The prosecutors should and will focus on the alleged history of abuse," he said.
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?"
Associated Press writer Kelli Kennedy contributed to this story.
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