St. Clair County District Attorney Richard Minor said Wednesday the findings should be available in time for a decision next month on how to proceed.
A 14-year-old boy was arrested and charged with murder in May after 9-year-old Katelynn Arnold was found hanging from a tree outside her home near Ragland.
Authorities say the boy told investigators he hanged the girl intentionally.
The youth's name hasn't been released because the murder charge was filed in juvenile court. But officials say the teenager remains in custody.
Katelynn and the teen were living together with relatives when she died.
