Police say Elkins had an accomplice, 15-year-old Dominique Lang, who has told investigators Elkins fired the gun. Lang also is charged with murder but will be tried later. He's expected to be a key witness against Elkins.
Both prosecutors and Elkins' defense attorneys declined to comment before the trial, citing a gag order by the judge. The boy's mother also declined to talk.
Kevin Gough, a public defender who is Elkins' lead attorney, has strongly suggested in pretrial motions that the real killers are the child's own parents.
"Other evidence of record suggests Sherry West is mentally unstable, gave several inconsistent accounts of how the crime transpired, and had a financial interest in the death of her son in the form of an insurance policy," Gough said in a court motion filed Aug. 5.
Defense attorneys have said in court filings they have audio recordings and documents showing the child's mother had dealings with Gerber Life Insurance Co. According to its website, Gerber Life sells life insurance policies for children starting as early as infancy. Coverage runs from $5,000 to $50,000.
Ashley Glassey, West's 21-year-old daughter, told television station WTLV of Jacksonville, Fla., soon after the shooting that her mother called her after Antonio was killed and asked, "How soon do you think the life insurance policy will send me a check?"
One of Elkins' lawyers interviewed Glassey on July 30 in Woodstown, N.J., where she was in jail for failing to appear in court in an unrelated case. According to a transcript, Glassey declined to confirm the story. "I don't want to incriminate anyone," she said.
Defense attorneys also point to lab tests by the Georgia Bureau of Investigation that found traces of gunshot residue on swabs taken from the hands of West and the boy's father, Louis Santiago. Reports filed in court say the GBI found a single microscopic particle of gunshot residue swabbed from the father's hands, while more than five particles showed up in swabs from West's hands.